Controlled release compositions for modulating free-radical induced damage and methods of use thereof

ABSTRACT

Disclosed herein are compositions and methods for the treatment of otic diseases or conditions with free-radical modulating agent compositions and formulations administered locally to an individual afflicted with an otic disease or condition, through direct application of these compositions and formulations onto or via perfusion into the targeted auris structure(s).

CROSS-REFERENCE

This patent application claims the benefit of U.S. ProvisionalApplication Ser. No. 61/082,450 filed Jul. 21, 2008; U.S. ProvisionalApplication Ser. No. 61/087,951 filed Aug. 11, 2008; U.S. ProvisionalApplication Ser. No. 61/094,384 filed Sep. 4, 2008; U.S. ProvisionalApplication Ser. No. 61/101,112 filed Sep. 29, 2008; and U.S.Provisional Application Ser. No. 61/140,033 filed Dec. 22, 2008; all ofwhich are incorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION

Vertebrates have a pair of ears, placed symmetrically on opposite sidesof the head. The ear serves as both the sense organ that detects soundand the organ that maintains balance and body position. The ear isgenerally divided into three portions: the outer ear, auris media (ormiddle ear) and the auris interna (or inner ear).

SUMMARY OF THE INVENTION

Described herein are compositions, formulations, manufacturing methods,therapeutic methods, uses, kits, and delivery devices for the controlledrelease of desired agents to at least one structure or region of theear. Provided herein are controlled release formulations for preventing,lessening or treating free-radical induced damage in the ear.

Disclosed herein, in certain embodiments, are controlled releasecompositions for treating otic and/or vestibular disorders comprising atherapeutically-effective amount of at least one modulator offree-radical induced damage and/or damage to the mitochondria(collectively referred herein as “free-radical modulating agent”), acontrolled release auris-acceptable excipient and an auris-acceptablevehicle.

In some embodiments, the free-radical damage modulating agent haslimited or no systemic release, systemic toxicity, poor pKcharacteristics, or combinations thereof. In some embodiments, the atleast one modulator of free-radical induced damage is an antioxidant, aniron chelator, a mitochondrial modulator, a sirtuin modulator, a nitricoxide (NO) and/or nitric oxide synthase (NOS) modulators and/or iNOSmodulators, or combinations thereof. In some embodiments, theantioxidant is N-acetylcysteine; vitamin E; vitamin C; vitamin A;lutein; selenium glutathione; melatonin; a polyphenol; a carotenoid;coenzyme Q-10; Ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one (alsocalled PZ 51 or DR3305); L-methionine; azulenyl nitrones;L-(+)-Ergothioneine; CAPE (caffeic acid phenethyl ester);dimethylthiourea; dimethylsulfoxide; disufenton sodium; pentoxifylline;MCI-186; Ambroxol; U-83836E; MitoQ (mitoquinone mesylate); Idebenone(2-(10-hydroxydecyl)-5,6-dimethoxy-3-methyl-cyclohexa-2,5-diene-1,4-dione);or combinations thereof. In some embodiments, the iron chelator isdesferrioxamine; hydroxybenzyl ethylene diamine; fullerenol-1,pyrrolidine dithiocarbamate; or combinations thereof. In someembodiments, the mitochondrial modulator is acetylcarnitine; lipoicacid; or combinations thereof. In some embodiments, the sirtuinmodulator is a stilbene, a chalcone, a flavone, an isoflavone, aflavanones, an anthocyanidin, a catechin, isonicotinamide, dipyridamole,ZM 336372, camptothecin, coumestrol, nordihydroguaiaretic acid,esculetin, SRT-1720, SRT-1460, SRT-2183, analogs thereof, orcombinations thereof. In some embodiments, the NO and/or NOS modulatoris aminoguanidine; 1-Amino-2-hydroxyguanidine p-toluensulfate; GED;bromocriptine mesylate; idebenone; SDMA; ADMA; L-NMMA; L-NMEA; D-MMA;L-NIL; L-NNA; L-NPA; L-NAME; L-VNIO; diphenyleneiodonium chloride;2-ethyl-2-thiopseudourea; haloperidol; L-NIO; MEG; SMT; SMTC; 7-Ni; nNOSinhibitor; 1,3-PBITU; L-thiocitrulline; TRIM; MTR-105; BBS-1; BBS-2;ONO-1714; GW273629; GW 274150; PPA250; AR-R17477; AR-R18512;spiroquinazolone; 1400W; S-NC; NTG; SNP; thapsigargin; VEGF; bradykinin;ATP; sphingosine-1-phosphate; estrogen; angiopoietin; acetylcholine;SIN-1; GEA 3162; GEA; GEA 5024; GEA 5538; SNAP; molsidomine; CNO-4;CNO-5; DEA/NO, IPA/NO, SPER/NO, SULFI/NO, OXI/NO, DETA/NO; orcombinations thereof.

In some embodiments, the composition further comprises a modulator offree-radical induced damage as an immediate release agent wherein theimmediate release modulator of free-radical induced damage is the sameagent as the controlled-release agent, a different modulator offree-radical induced damage, an additional therapeutic agent, or acombination thereof. In some embodiments, the composition furthercomprises an additional therapeutic agent. In some embodiments, theadditional therapeutic agent is a glutamate receptor modulator, a growthfactor, a local anesthetic agent, an anti-emetic agent or combinationsthereof. In some embodiments, the additional therapeutic agent is animmediate release agent. In some embodiments, the additional therapeuticagent is a controlled release agent.

Disclosed herein are controlled release formulations for delivering afree-radical modulating agent to the ear. In some embodiments, thecomposition is administered so that the composition is in contact withthe crista fenestrae cochleae, the round window or the tympanic cavity.In one aspect the composition is administered by intratympanicinjection.

The auris formulations and therapeutic methods described herein havenumerous advantages that overcome the previously-unrecognizedlimitations of formulations and therapeutic methods described in priorart.

Sterility

The environment of the inner ear is an isolated environment. Theendolymph and the perilymph are static fluids and are not in contiguouscontact with the circulatory system. The blood-labyrinth-barrier (BLB),which includes a blood-endolymph barrier and a blood-perilymph barrier,consists of tight junctions between specialized epithelial cells in thelabyrinth spaces (i.e., the vestibular and cochlear spaces). Thepresence of the BLB limits delivery of active agents (e.g., free-radicalmodulating agents) to the isolated microenvironment of the inner ear.Auris hair cells are bathed in endolymphatic or perilymphatic fluids andcochlear recycling of potassium ions is important for hair cellfunction. When the inner ear is infected, there is an influx ofleukocytes and/or immunoglobins (e.g. in response to a microbialinfection) into the endolymph and/or the perilymph and the delicateionic composition of inner ear fluids is upset by the influx ofleukocytes and/or immunoglobins. In certain instances, a change in theionic composition of inner ear fluids results in hearing loss, loss ofbalance and/or ossification of auditory structures. In certaininstances, even trace amounts of pyrogens and/or microbes can triggerinfections and related physiological changes in the isolatedmicroenvironment of the inner ear.

Due to the susceptibilty of the inner ear to infections, aurisformulations require a level of sterility that has not been recognizedhitherto in prior art. Provided herein are auris formulations that aremanufactured with low bioburden or sterilized with stringent steriltyrequirements and are suitable for administration to the middle and/orinner ear. In some embodiments, the auris compatible compositionsdescribed herein are substantially free of pyrogens and/or microbes.

Compatibility with Inner Ear Environment

Described herein are otic formulations with an ionic balance that iscompatible with the perilymph and/or the endolymph and does not causeany change in cochlear potential. In specific embodiments,osmolarity/osmolality of the present formulations is adjusted, forexample, by the use of appropriate salt concentrations (e.g.,concentration of sodium salts) or the use of tonicity agents whichrenders the formulations endolymph-compatible and/orperilymph-compatible (i.e. isotonic with the endolymph and/orperilymph). In some instances, the endolymph-compatible and/orperilymph-compatible formulations described herein cause minimaldisturbance to the environment of the inner ear and cause minimumdiscomfort (e.g, vertigo) to a mammal (e.g., a human) uponadministration. Further, the formulations comprise polymers that arebiodegradable and/or dispersable, and/or otherwise non-toxic to theinner ear environment. In some embodiments, the formulations describedherein are free of preservatives and cause minimal disturbance (e.g.,change in pH or osmolarity, irritation) in auditory structures. In someembodiments, the formulations described herein comprise antioxidantsthat are non-irritating and/or non-toxic to otic structures.

Dosing Frequency

The current standard of care for auris formulations requires multipleadministrations of drops or injections (e.g. intratympanic injections)over several days (e.g., up to two weeks), including schedules ofreceiving multiple injections per day. In some embodiments, aurisformulations described herein are controlled release formulations, andare administered at reduced dosing frequency compared to the currentstandard of care. In certain instances, when an auris formulation isadministered via intratympanic injection, a reduced frequency ofadministration alleviates discomfort caused by multiple intratympanicinjections in individuals undergoing treatment for a middle and/or innerear disease, disorder or condition. In certain instances, a reducedfrequency of administration of intratympanic injections reduces the riskof permanent damage (e.g., perforation) to the ear drum. Theformulations described herein provide a constant, sustained, extended,delayed or pulsatile rate of release of an active agent into the innerear environment and thus avoid any variability in drug exposure intreatment of otic disorders. In some embodiments, the compositions ordevices described herein avoid variability in contact with the roundwindow (a major site of inner ear drug absorption). In some embodiments,the compositions or devices described herein avoid a short residencetime in the middle ear.

Therapeutic Index

Auris formulations described herein are administered into the ear canal,or in the vestibule of the ear. Access to, for example, the vestibularand cochlear apparatus will occur through the auris media including theround window membrane, the oval window/stapes footplate, the annularligament and through the otic capsule/temporal bone. Otic administrationof the formulations described herein avoids toxicity associated withsystemic administration (e.g., hepatotoxicity, cardiotoxicity,gastrointestinal side effects, renal toxicity) of the active agents. Insome instances, localized administration in the ear allows an activeagent to reach a target organ (e.g., inner ear) in the absence ofsystemic accumulation of the active agent. In some instances, localadministration to the ear provides a higher therapeutic index for anactive agent that would otherwise have dose-limiting systemic toxicity.

Prevention of Drainage into Eustachian Tube

In some instances, a disadvantage of liquid formulations is theirpropensity to drip into the eustachian tube and cause rapid clearance ofthe formulation from the inner ear. Provided herein, in certainembodiments, are auris formulations comprising polymers that gel at bodytemperature and remain in contact with the target auditory surfaces(e.g., the round window) for extended periods of time. In someembodiments, the formulations further comprise mucoadhesives that allowthe formulations to adhere to otic mucosal surfaces. In some instances,the auris formulations described herein avoid attenuation of therapeuticbenefit due to drainage or leakage of active agents via the eustachiantube.

Description of Certain Embodiments

Described herein are controlled release compositions and devices fortreating otic disorders comprising a therapeutically-effective amount ofa free-radical modulating agent, a controlled release auris-acceptableexcipient and an auris-acceptable vehicle. In one aspect, the controlledrelease auris-acceptable excipient is chosen from an auris-acceptablepolymer, an auris-acceptable viscosity enhancing agent, anauris-acceptable gel, an auris-acceptable paint, an auris-acceptablefoam, an auris-acceptable microsphere or microparticle, anauris-acceptable hydrogel, an auris-acceptable in situ forming spongymaterial, an auris-acceptable actinic radiation curable gel, anauris-acceptable liposome, an auris-acceptable nanocapsule ornanosphere, an auris-acceptable thermoreversible gel or combinationsthereof. In some embodiments, the hydrogel comprises excipients selectedfrom Chitosan-glycerophosphate (CGP); PEG-PLGA-PEG triblock polymers;PEO-PPO-PEO triblock copolymers; and Chitosan-glycerophosphate withdrug-loaded liposomes. In further embodiments, the auris-acceptableviscosity enhancing agent is a cellulose, a cellulose ether, alginate,polyvinylpyrrolidone, a gum, a cellulosic polymer or combinationsthereof. In yet another embodiment, the auris-acceptable viscosityenhancing agent is present in an amount sufficient to provide aviscosity of between about 1000 to about 1,000,000 centipoise. In stillanother aspect, the auris-acceptable viscosity enhancing agent ispresent in an amount sufficient to provide a viscosity of between about50,000 to about 1,000,000 centipoise. In some embodiments, thefree-radical modulating agent formulations or compositions are optimalfor osmolality or osmolarity of the target auris structure to ensurehomeostasis is maintained.

In some embodiments, the compositions are formulated for pH, and apractical osmolality or osmolarity to ensure that homeostasis of thetarget auris structure is maintained. A perilymph-suitableosmolarity/osmolality is a practical/deliverable osmolarity/osmolalitythat maintains the homeostasis of the target auris structure duringadministration of the pharmaceutical formulations described herein.

For example, the osmolarity of the perilymph is between about 270-300mOsm/L, and the compositions described herein are optionally formulatedto provide a practical osmolarity of about 150 to about 1000 mOsm/L. Incertain embodiments, the formulations described herein provide apractical and/or deliverable osmolarity within about 150 to about 500mOsm/L at the target site of action (e.g., the inner ear and/or theperilymph and/or the endolymph). In certain embodiments, theformulations described herein provide a practical osmolarity withinabout 200 to about 400 mOsm/L at the target site of action (e.g., theinner ear and/or the perilymph and/or the endolymph). In certainembodiments, the formulations described herein provide a practicalosmolarity within about 250 to about 320 mOsm/L at the target site ofaction (e.g., the inner ear and/or the perilymph and/or the endolymph).In certain embodiments, the formulations described herein provide aperilymph-suitable osmolarity within about 150 to about 500 mOsm/L,about 200 to about 400 mOsm/L or about 250 to about 320 mOsm/L at thetarget site of action (e.g., the inner ear and/or the perilymph and/orthe endolymph). In certain embodiments, the formulations describedherein provide a perilymph-suitable osmolality within about 150 to about500 mOsm/kg, about 200 to about 400 mOsm/kg or about 250 to about 320mOsm/kg at the target site of action (e.g., the inner ear and/or theperilymph and/or the endolymph). Similarly, the pH of the perilymph isabout 7.2-7.4, and the pH of the present formulations is formulated(e.g., with the use of buffers) to provide a perilymph-suitable pH ofabout 5.5 to about 9.0, about 6.0 to about 8.0 or about 7.0 to about7.6. In certain embodiments, the pH of the formulations is within about6.0 to about 7.6. In certain instances, the pH of the endolymph is about7.2-7.9, and the pH of the present formulations is formulated (e.g.,with the use of buffers) to be within about 5.5 to about 9.0, withinabout 6.5 to about 8.0 or within about 7.0 to about 7.6.

In some aspects, the controlled-release auris-acceptable excipient isbiodegradable. In some aspects the controlled release auris-acceptableexcipient is bioeliminated (e.g., degraded and/or eliminated throughurine, feces or other routes of elimination). In another aspect, thecontrolled release composition further comprises an auris-acceptablemucoadhesive, an auris-acceptable penetration enhancer or anauris-acceptable bioadhesive.

In one aspect, the controlled release free-radical modulating agentcomposition is delivered using a drug delivery device, which is a needleand syringe, a pump, a microinjection device or combinations thereof. Insome embodiments, the free-radical modulating agent of the controlledrelease composition has limited or no systemic release, is toxic whenadministered systemically, has poor pK characteristics or combinationsthereof. In some aspects, the free-radical modulating agent is a smallmolecule.

Also disclosed herein are methods for the treatment of otic disorderscomprising local administration of a free-radical modulator controlledrelease formulation to the ear. Otic disorders treatable with theformulations disclosed herein include ototoxicity, excitotoxicity,sensorineural hearing loss, and/or presbycusis. In certain embodiments,a method for treating an otic disorder comprises administering any ofthe compositions disclosed herein at least once every 3, 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14 or 15 days; or at least once a week, once everytwo weeks, once every three weeks, once every four weeks, once everyfive weeks, or once every six weeks; or once a month, once every twomonths, once every three months, once every four months, once every fivemonths, once every six months, once every seven months, once every eightmonths, once every nine months, once every ten months, once every elevenmonths, or once every twelve months.

In particular embodiments, the controlled release formulations describedherein provide a sustained dose of free-radical modulating agent to theinner ear between subsequent doses of the controlled releaseformulation. That is, taking one example only, if new doses of thefree-radical modulating agent controlled release formulation areadminstered via intratympanic injection to the round window membraneevery 10 days, then the controlled release formulation provides aneffective dose of free-radical modulating agent to the inner ear (e.g.,across the round window membrane) during that 10-day period.

Provided herein is a pharmaceutical composition or device comprising anamount of a free-radical modulator that is therapeutically effective fortreating an otic disease or condition associated with free-radicalinduced damage, the pharmaceutical composition or device comprisingsubstantially low degradation products of the free-radical modulatingagent, the pharmaceutical composition or device further comprising twoor more characteristics selected from:

-   -   (i) between about 0.1% to about 10% by weight of the        free-radical modulating agent, or pharmaceutically acceptable        prodrug or salt thereof,    -   (ii) between about 14% to about 21% by weight of a        polyoxyethylene-polyoxypropylene triblock copolymer of general        formula E106 P70 E106;    -   (iii) sterile water, q.s., buffered to provide a pH between        about 5.5 and about 8.0;    -   (iv) multiparticulate free-radical modulating agent;    -   (v) a gelation temperature between about 19° C. to about 42° C.;    -   (vi) less than about 50 colony forming units (cfu) of        microbiological agents per gram of formulation;    -   (vii) less than about 5 endotoxin units (EU) per kg of body        weight of a subject;    -   (viii) a mean dissolution time of about 30 hours for the        free-radical modulating agent; and    -   (ix) an apparent viscosity of about 100,000 cP to about 500,000        cP.

In some embodiments, the pharmaceutical composition comprises at leastthree of the aforementioned characteristics. In some embodiments, thepharmaceutical composition comprises at least four of the aforementionedcharacteristics. In some embodiments, the pharmaceutical compositioncomprises at least five of the aforementioned characteristics. In someembodiments, the pharmaceutical composition comprises at least six ofthe aforementioned characteristics. In some embodiments, thepharmaceutical composition comprises at least seven of theaforementioned characteristics. In some embodiments, the pharmaceuticalcomposition comprises all of the aforementioned characteristics.

In some embodiments, a pharmaceutical composition or device describedherein comprises:

-   -   (i) between about 0.1% to about 10% by weight of the        free-radical modulating agent, or pharmaceutically acceptable        prodrug or salt thereof;    -   (ii) between about 14% to about 21% by weight of a        polyoxyethylene-polyoxypropylene triblock copolymer of general        formula E106 P70 E106; and    -   (iii) multiparticulate free-radical modulating agent; and    -   (iv) an apparent viscosity of about 100,000 cP to about 500,000        cP.

In some embodiments, a pharmaceutical composition or device describedherein comprises:

-   -   (i) between about 0.1% to about 10% by weight of the        free-radical modulating agent, or pharmaceutically acceptable        prodrug or salt thereof;    -   (ii) between about 14% to about 21% by weight of a        polyoxyethylene-polyoxypropylene triblock copolymer of general        formula E106 P70 E106;    -   (iii) multiparticulate free-radical modulating agent;    -   (iv) a gelation temperature between about 19° C. to about 42°        C.; and    -   (v) a mean dissolution time of about 30 hours for the        free-radical modulating agent.

In some embodiments, a pharmaceutical composition or device describedherein comprises:

-   -   (i) multiparticulate free-radical modulating agent;    -   (ii) a mean dissolution time of about 30 hours for the        free-radical modulating agent.    -   (iii) a gelation temperature between about 19° C. to about 42°        C.; and    -   (iv) an apparent viscosity of about 100,000 cP to about 500,000        cP.

In some embodiments a pharmaceutical composition or device describedabove provides a practical osmolarity between about 150 and 500 mOsm/L.In some embodiments a pharmaceutical composition or device describedabove provides a practical osmolarity between about 200 and 400 mOsm/L.In some embodiments a pharmaceutical composition or device describedabove provides a practical osmolarity between about 250 and 320 mOsm/L.

In some embodiments, the free-radical modulating agent is released fromthe pharmaceutical composition or device described above for a period ofat least 3 days. In some embodiments, the free-radical modulating agentis released from the pharmaceutical composition or device describedabove for a period of at least 5 days. In some embodiments, thefree-radical modulating agent is released from the pharmaceuticalcomposition or device described above for a period of at least 10 days.In some embodiments, the free-radical modulating agent is released fromthe pharmaceutical composition or device described above for a period ofat least 14 days. In some embodiments, the free-radical modulating agentis released from the pharmaceutical composition or device describedabove for a period of at least one month.

In some embodiments, a pharmaceutical composition or device describedabove comprises a free-radical modulating agent as a neutral compound, afree acid, a free base, a salt or a prodrug. In some embodiments, apharmaceutical composition or device described above comprisesfree-radical modulating agent as a neutral compound, a free acid, a freebase, a salt or a prodrug, or a combination thereof. In someembodiments, the pharmaceutical composition or device further comprisesthe free-radical modulating agent, or pharmaceutically acceptable saltthereof, prodrug or combination thereof as an immediate release agent.

In some embodiments, a pharmaceutical composition or device describedabove is an auris-acceptable thermoreversible gel. In some embodimentsof the pharmaceutical composition or device, thepolyoxyethylene-polyoxypropylene triblock copolymer is bioeliminated.

In some embodiments the pharmaceutical composition or device comprisesthe free-radical modulating agent as multiparticulates. In someembodiments of the pharmaceutical composition or device, thefree-radical modulating agent is essentially in the form of micronizedparticles. In some embodiments of the pharmaceutical composition ordevice, the free-radical modulating agent is in the form of micronizedfree-radical modulating agent powder.

In some embodiments, a pharmaceutical composition or device describedabove comprises about 10% of a polyoxyethylene-polyoxypropylene triblockcopolymer of general formula E106 P70 E106 by weight of the composition.In some embodiments, a pharmaceutical composition or device describedabove comprises about 15% of a polyoxyethylene-polyoxypropylene triblockcopolymer of general formula E106 P70 E106 by weight of the composition.In some embodiments, a pharmaceutical composition or device describedabove comprises about 20% of a polyoxyethylene-polyoxypropylene triblockcopolymer of general formula E106 P70 E106 by weight of the composition.In some embodiments, a pharmaceutical composition or device describedabove comprises about 25% of a polyoxyethylene-polyoxypropylene triblockcopolymer of general formula E106 P70 E106 by weight of the composition.

In some embodiments, a pharmaceutical composition or device describedabove comprises about 0.01% of a free-radical modulating agent, orpharmaceutically acceptable prodrug or salt thereof, by weight of thecomposition. In some embodiments, a pharmaceutical composition or devicedescribed above comprises about 0.05% of a free-radical modulatingagent, or pharmaceutically acceptable prodrug or salt thereof, by weightof the composition. In some embodiments, a pharmaceutical composition ordevice described above comprises about 0.1% of a free-radical modulatingagent, or pharmaceutically acceptable prodrug or salt thereof, by weightof the composition. In some embodiments, a pharmaceutical composition ordevice described above comprises about 1% of a free-radical modulatingagent, or pharmaceutically acceptable prodrug or salt thereof, by weightof the composition. In some embodiments, a pharmaceutical composition ordevice described above comprises about 2.5% of a free-radical modulatingagent, or pharmaceutically acceptable prodrug or salt thereof, by weightof the composition. In some embodiments, a pharmaceutical composition ordevice described above comprises about 5% of a free-radical modulatingagent, or pharmaceutically acceptable prodrug or salt thereof, by weightof the composition. In some embodiments, a pharmaceutical composition ordevice described above comprises about 10% of a free-radical modulatingagent, or pharmaceutically acceptable prodrug or salt thereof, by weightof the composition. In some embodiments, a pharmaceutical composition ordevice described above comprises about 20% of a free-radical modulatingagent, or pharmaceutically acceptable prodrug or salt thereof, by weightof the composition. In some embodiments, a pharmaceutical composition ordevice described above comprises about 30% of a free-radical modulatingagent, or pharmaceutically acceptable prodrug or salt thereof, by weightof the composition. In some embodiments, a pharmaceutical composition ordevice described above comprises about 40% of a free-radical modulatingagent, or pharmaceutically acceptable prodrug or salt thereof, by weightof the composition. In some embodiments, a pharmaceutical composition ordevice described above comprises about 50% of a free-radical modulatingagent, or pharmaceutically acceptable prodrug or salt thereof, by weightof the composition.

In some embodiments, a pharmaceutical composition or device describedabove has a pH between about 5.5 to about 8.0. In some embodiments, apharmaceutical composition or device described above has a pH betweenabout 6.0 to about 8.0. In some embodiments, a pharmaceuticalcomposition or device described above has a pH between about 6.0 toabout 7.6. In some embodiments, a pharmaceutical composition or devicedescribed above has a pH between about 7.0 to about 7.6.

In some embodiments, a pharmaceutical composition or device describedabove contains less than 100 colony forming units (cfu) ofmicrobiological agents per gram of formulation. In some embodiments, apharmaceutical composition or device described above contains less than50 colony forming units (cfu) of microbiological agents per gram offormulation. In some embodiments, a pharmaceutical composition or devicedescribed above contains less than 10 colony forming units (cfu) ofmicrobiological agents per gram of formulation.

In some embodiments, a pharmaceutical composition or device describedabove contains less than 5 endotoxin units (EU) per kg of body weight ofa subject. In some embodiments, a pharmaceutical composition or devicedescribed above contains less than 4 endotoxin units (EU) per kg of bodyweight of a subject.

In some embodiments a pharmaceutical composition or device describedabove provides a gelation temperature between about between about 19° C.to about 42° C. In some embodiments a pharmaceutical composition ordevice described above provides a gelation temperature between aboutbetween about 19° C. to about 37° C. In some embodiments apharmaceutical composition or device described above provides a gelationtemperature between about between about 19° C. to about 30° C.

In some embodiments, the pharmaceutical composition or device is anauris-acceptable thermoreversible gel. In some embodiments, thepolyoxyethylene-polyoxypropylene triblock copolymer is biodegradableand/or bioeliminated (e.g., the copolymer is eliminated from the body bya biodegradation process, e.g., elimination in the urine, the feces orthe like). In some embodiments, a pharmaceutical composition or devicedescribed herein further comprises a mucoadhesive. In some embodiments,a pharmaceutical composition or device described herein furthercomprises a penetration enhancer. In some embodiments, a pharmaceuticalcomposition or device described herein further comprises a thickeningagent. In some embodiments, a pharmaceutical composition or devicedescribed herein further comprises a dye.

In some embodiments, a pharmaceutical composition or device describedherein further comprises a drug delivery device selected from a needleand syringe, a pump, a microinjection device, a wick, an in situ formingspongy material or combinations thereof.

In some embodiments, a pharmaceutical composition or device describedherein is a pharmaceutical composition or device wherein thefree-radical modulating agent, or pharmaceutically acceptable saltthereof, has limited or no systemic release, systemic toxicity, poor PKcharacteristics, or combinations thereof. In some embodiments of thepharmaceutical compositions or devices described above, the free-radicalmodulating agent is in the form of a neutral molecule, free base, a freeacid, a salt, a prodrug, or a combination thereof. In some embodimentsof the pharmaceutical compositions or devices described above, thefree-radical modulating agent is administered in the form of a esterprodrug or a phosphate prodrug. In some embodiments pharmaceuticalcompositions or devices described above comprise one or morefree-radical modulating agent, or pharmaceutically acceptable saltthereof, prodrug or combination thereof as an immediate release agent.

In some embodiments, pharmaceutical compositions or devices describedherein are pharmaceutical compositions or devices wherein the pH of thepharmaceutical composition or device is between about 6.0 to about 7.6.

In some embodiments of the pharmaceutical compositions or devicesdescribed herein, the ratio of a polyoxyethylene-polyoxypropylenetriblock copolymer of general formula E106 P70 E106 to a thickeningagent is from about 40:1 to about 5:1. In some embodiments, thethickening agent is carboxymethyl cellulose, hydroxypropyl cellulose orhydroxypropyl methylcellulose.

In some embodiments, the otic disease or condition is ototoxicity,excitotoxicity, sensorineural hearing loss, and/or presbycusis.

Also provided herein is a method of alleviating free-radical induceddamage associated with an otic intervention comprising administering toan individual in need thereof an intratympanic composition or devicecomprising a therapeutically effective amount of a free-radicalmodulating agent, the composition or device comprising substantially lowdegradation products of the free-radical modulating agent, thecomposition or device further comprising two or more characteristicsselected from:

-   -   (i) between about 0.1% to about 10% by weight of the        free-radical modulating agent, or pharmaceutically acceptable        prodrug or salt thereof;    -   (ii) between about 14% to about 21% by weight of a        polyoxyethylene-polyoxypropylene triblock copolymer of general        formula E106 P70 E106;    -   (iii) sterile water, q.s., buffered to provide a pH between        about 5.5 and about 8.0;    -   (iv) multiparticulate free-radical modulating agent;    -   (v) a gelation temperature between about 19° C. to about 42° C.;    -   (vi) less than about 50 colony forming units (cfu) of        microbiological agents per gram of formulation;    -   (vii) less than about 5 endotoxin units (EU) per kg of body        weight of a subject;    -   (viii) a mean dissolution time of about 30 hours; and    -   (ix) an apparent viscosity of about 100,000 cP to about 500,000        cP.

In some embodiments, the pharmaceutical composition comprises at leastthree of the aforementioned characteristics. In some embodiments, thepharmaceutical composition comprises at least four of the aforementionedcharacteristics. In some embodiments, the pharmaceutical compositioncomprises at least five of the aforementioned characteristics. In someembodiments, the pharmaceutical composition comprises at least six ofthe aforementioned characteristics. In some embodiments, thepharmaceutical composition comprises at least seven of theaforementioned characteristics. In some embodiments, the pharmaceuticalcomposition comprises all of the aforementioned characteristics.

Also provided herein is a method of treating an otic disease orcondition associated with free-radical induced damage comprisingadministering to an individual in need thereof an intratympaniccomposition or device comprising a therapeutically effective amount of afree-radical modulating agent, the composition or device comprisingsubstantially low degradation products of the free-radical modulatingagent, the composition or device further comprising two or morecharacteristics selected from:

-   -   (i) between about 0.1% to about 10% by weight of the        free-radical modulating agent, or pharmaceutically acceptable        prodrug or salt thereof;    -   (ii) between about 14% to about 21% by weight of a        polyoxyethylene-polyoxypropylene triblock copolymer of general        formula E106 P70 E106;    -   (iii) sterile water, q.s., buffered to provide a pH between        about 5.5 and about 8.0;    -   (iv) multiparticulate free-radical modulating agent;    -   (v) a gelation temperature between about 19° C. to about 42° C.;    -   (vi) less than about 50 colony forming units (cfu) of        microbiological agents per gram of formulation;    -   (vii) less than about 5 endotoxin units (EU) per kg of body        weight of a subject;    -   (viii) a mean dissolution time of about 30 hours for the        free-radical modulating agent; and    -   (ix) an apparent viscosity of about 100,000 cP to about 500,000        cP.        In some embodiments, the pharmaceutical composition comprises at        least three of the aforementioned characteristics. In some        embodiments, the pharmaceutical composition comprises at least        four of the aforementioned characteristics. In some embodiments,        the pharmaceutical composition comprises at least five of the        aforementioned characteristics. In some embodiments, the        pharmaceutical composition comprises at least six of the        aforementioned characteristics. In some embodiments, the        pharmaceutical composition comprises at least seven of the        aforementioned characteristics. In some embodiments, the        pharmaceutical composition comprises all of the aforementioned        characteristics.

In some embodiments of the methods described above, the free-radicalmodulating agent is released from the composition or device for a periodof at least 3 days. In some embodiments of the methods described above,the free-radical modulating agent is released from the composition ordevice for a period of at least 5 days. In some embodiments of themethods described above, the free-radical modulating agent is releasedfrom the composition or device for a period of at least 10 days. In someembodiments of the method described above, the free-radical modulatingagent is essentially in the form of micronized particles.

In some embodiments of the methods, a pharmaceutical composition ordevice described above is administered in combination with an oticintervention. In some embodiments of the methods, a pharmaceuticalcomposition or device described above is administered before an oticintervention. In some embodiments of the methods, a pharmaceuticalcomposition or device described above is administered during an oticintervention. In some embodiments of the methods, a pharmaceuticalcomposition or device described above is administered after an oticintervention.

In some embodiments, the otic and/or vestibular disorder is ototoxicity,excitotoxicity, sensorineural hearing loss, and/or presbycusis.

BRIEF DESCRIPTION OF FIGURES

FIG. 1. illustrates a comparison of non-sustained release and sustainedrelease formulations.

FIG. 2 illustrates the effect of concentration on the viscosity ofaqueous solutions of Blanose refined CMC.

FIG. 3 illustrates the effect of concentration on the viscosity ofaqueous solutions of Methocel.

FIG. 4 illustrates the anatomy of the ear

FIG. 5 shows predicted tunable release of an active agent from fourcompositions.

DETAILED DESCRIPTION OF THE INVENTION

Provided herein are controlled release free-radical modulating agentcompositions and formulations for the treatment of otic disorders,including ototoxicity, excitotoxicity, sensorineural hearing loss,and/or presbycusis. Provided herein, in some embodiments, are controlledrelease auris-acceptable compositions that prevent, relieve, reverse orameliorate the degeneration of neurons and/or hair cells of the aurisdue to free-radicals and/or the dysfunction of the mitochondria. In oneembodiment, the controlled release auris-acceptable compositioncomprises a therapeutically effective amount of at least onefree-radical modulating agent (also referred to as a “modulator offree-radical induced damage” or “free-radical induced damagemodulator”), a controlled release auris-acceptable excipient, and anauris-acceptable vehicle.

A few therapeutic products are available to prevent and/or ameliorateototoxicity, excitotoxicity, sensorineural hearing loss, and/orpresbycusis; however, systemic routes via oral, intravenous orintramuscular routes are currently used to deliver these therapeuticagents.

Systemic free-radical modulating agent administration for the treatmentof otic disorders, e.g., ototoxicity, excitotoxicity, sensorineuralhearing loss, and/or presbycusis, may create a potential inequality indrug concentration with higher circulating levels in the serum, andlower levels in the target auris interna organ structures. As a result,fairly large amounts of drug are required to overcome this inequality inorder to deliver sufficient, therapeutically effective quantities to theinner ear. Further, bioavailability is often decreased due to metabolismof the drug by the liver. For example, resveratrol is so rapidlymetabolized by the liver into glucuronate and sulfonate such that onlytrace amounts are found in the blood after ingestion.

In addition, systemic drug administration may increase the likelihood ofsystemic toxicities and adverse side effects as a result of the highserum amounts required to effectuate sufficient local delivery to thetarget site. Systemic toxicities may also occur as a result of liverbreakdown and processing of the therapeutic agents, forming toxicmetabolites that effectively erase any benefit attained from theadministered therapeutic.

To overcome the toxic and attendant undesired side effects of systemicdelivery of free-radical modulating agents (which are generallyunderstood to be toxic to cells), disclosed herein are methods andcompositions for local delivery of free-radical modulating agents toauris media and/or auris interna structures. Access to, for example, thevestibular and cochlear apparatus will occur through the auris media orauris interna, including the round window membrane, the ovalwindow/stapes footplate, the annular ligament and through the oticcapsule/temporal bone. In further or alternative embodiments, the auriscontrolled-release formulations are capable of being administered on ornear the round window membrane via intratympanic injection. In otherembodiments, the auris controlled release formulations are administeredon or near the round window or the crista fenestrae cochleae throughentry via a post-auricular incision and surgical manipulation into ornear the round window or the crista fenestrae cochleae area.Alternatively, the auris controlled release formulation is applied viasyringe and needle, wherein the needle is inserted through the tympanicmembrane and guided to the area of the round window or crista fenestraecochleae.

In addition, localized treatment of the auris interna also affords theuse of previously undesired therapeutic agents, including agents withpoor pK profiles, poor uptake, and/or low systemic release. Because ofthe localized targeting of the free-radical modulating agentformulations and compositions, as well as the biological blood barrierpresent in the auris interna, the risk of adverse effects will bereduced as a result of treatment with previously characterized toxic orineffective free-radical modulating agent. Accordingly, alsocontemplated within the scope of the embodiments herein is the use offree radical modulating agents to prevent, and/or ameliorateototoxicity, excitotoxicity, sensorineural hearing loss, and/orpresbycusis, including therapeutic agents that have been previouslyrejected by practitioners because of the ineffectiveness ofsystemically-administered free-radical modulating agents.

In some embodiments, the composition further comprises a free-radicalmodulator as an immediate release agent wherein the immediate releasefree-radical modulating agent is the same agent as thecontrolled-release agent, a different free-radical modulating agent, anadditional therapeutic agent, or a combination thereof.

Intratympanic injection of therapeutic agents is the technique ofinjecting a therapeutic agent behind the tympanic membrane into theauris media and/or auris interna. Despite early success with thistechnique (Schuknecht, Laryngoscope (1956) 66, 859-870) some challengesdo remain. For example, access to the round window membrane, the site ofdrug absorption into the auris interna, can be challenging.

However, intra-tympanic injections create several unrecognized problemsnot addressed by currently available treatment regimens, such aschanging the osmolarity and pH of the perilymph and endolymph, andintroducing pathogens and endotoxins that directly or indirectly damageinner ear structures. One of the reasons the art may not have recognizedthese problems is that there are no approved intra-tympaniccompositions: the inner ear provides sui generis formulation challenges.Thus, compositions developed for other parts of the body have little tono relevance for an intra-tympanic composition.

There is no guidance in the prior art regarding requirements (e.g.,level of sterility, pH, osmolarity) for otic formulations that aresuitable for administration to humans. There is wide anatomicaldisparity between the ears of animals across species. A consequence ofthe inter-species differences in auditory structures is that animalmodels of inner ear disease are often unreliable as a tool for testingtherapeutics that are being developed for clinical approval.

Provided herein are otic formulations that meet stringent criteria forpH, osmolarity, ionic balance, sterility, endotoxin and/or pyrogenlevels. The auris compositions described herein are compatible with themicroenvironment of the inner ear (e.g., the perilymph) and are suitablefor administration to humans. In some embodiments, the formulationsdescribed herein comprise dyes and aid visualization of the administeredcompositions obviating the need for invasive procedures (e.g., removalof perilymph) during preclinical and/or clinical development ofintratympanic therapeutics.

Provided herein are controlled release free-radical modulating agentformulations and compositions to locally treat targeted aurisstructures, thereby avoiding side effects as a result of systemicadministration of the free-radical modulating agent formulations andcompositions. The locally applied free-radical modulating agentformulations and compositions and devices are compatible with thetargeted auris structures, and administered either directly to thedesired targeted auris structure, e.g. the cochlear region, the tympaniccavity or the external ear, or administered to a structure in directcommunication with areas of the auris interna, including but not limitedto the round window membrane, the crista fenestrae cochleae or the ovalwindow membrane. By specifically targeting an auris structure, adverseside effects as a result of systemic treatment are avoided. Moreover,clinical studies have shown the benefit of having long term exposure ofdrug to the perilymph of the cochlea, for example with improved clinicalefficacy of sudden hearing loss when the therapeutic agent is given onmultiple occasions. Thus, by providing a controlled release free-radicalmodulating agent formulation or composition to treat otic disorders, aconstant, and/or extended source of free-radical modulating agent isprovided to the individual or patient suffering from an otic disorder,reducing or eliminating variabilities in treatment. Accordingly, oneembodiment disclosed herein is to provide a composition that enables atleast one free-radical modulating agent to be released intherapeutically effective doses either at variable or constant ratessuch as to ensure a continuous release of the at least one agent. Insome embodiments, the free-radical modulating agents disclosed hereinare administered as an immediate release formulation or composition. Inother embodiments, the free-radical modulating agents are administeredas a sustained release formulation, released either continuously,variably or in a pulsatile manner, or variants thereof. In still otherembodiments, free-radical modulating agent formulation is administeredas both an immediate release and sustained release formulation, releasedeither continuously, variably or in a pulsatile manner, or variantsthereof. The release is optionally dependent on environmental orphysiological conditions, for example, the external ionic environment(see, e.g. Oros® release system, Johnson & Johnson).

In addition, the auris-acceptable controlled-release free-radicalmodulating agent formulations and treatments described herein areprovided to the target ear region of the individual in need, includingthe inner ear, and the individual in need is additionally administeredan oral dose of free-radical modulating agent. In some embodiments, theoral dose of free-radical modulating agent is administered prior toadministration of the auris-acceptable controlled-release free-radicalmodulating agent formulation, and then the oral dose is tapered off overthe period of time that the auris-acceptable controlled-releasefree-radical modulating agent formulation is provided. Alternatively,the oral dose of free-radical modulating agent is administered duringadministration of the auris-acceptable controlled-release free-radicalmodulating agent formulation, and then the oral dose is tapered off overthe period of time that the auris-acceptable controlled-releasefree-radical modulating agent formulation is provided. Alternatively,the oral dose of free-radical modulating agent is administered afteradministration of the auris-acceptable controlled-release free-radicalmodulating agent formulation has been initiated, and then the oral doseis tapered off over the period of time that the auris-acceptablecontrolled-release free-radical modulating agent formulation isprovided.

In addition, the free-radical modulating agent pharmaceuticalcompositions or formulations or devices included herein also includecarriers, adjuvants, such as preserving, stabilizing, wetting oremulsifying agents, solution promoters, salts for regulating the osmoticpressure, and/or buffers. Such carriers, adjuvants, and other excipientswill be compatible with the environment in the targeted aurisstructure(s). Accordingly, specifically contemplated are carriers,adjuvants and excipients that lack ototoxicity or are minimally ototoxicin order to allow effective treatment of the otic disorders contemplatedherein with minimal side effects in the targeted regions or areas.

Intratympanic injection of composition or devices creates severaladditional problems that must also be addressed before the compositionor device can be administered. For example, there are many excipientsthat are ototoxic. While these excipients can be used when formulatingan active agent for delivery by another method (e.g., topical), theiruse should be limited, reduced or eliminated when formulating acomposition or device to be administered to the ear due to theirototoxic effects.

By way of non-limiting example, the use of the following commonly usedsolvents should be limited, reduced or eliminated when formulatingagents for administration to the ear: alcohols, propylene glycol, andcyclohexane. Thus, in some embodiments, a device disclosed herein isfree or substantially free of alcohols, propylene glycol, andcyclohexane. In some embodiments, a device disclosed herein comprisesless than about 50 ppm of each of alcohols, propylene glycol, andcyclohexane. In some embodiments, a device disclosed herein comprisesless than about 25 ppm of each of alcohols, propylene glycol, andcyclohexane. In some embodiments, a device disclosed herein comprisesless than about 20 ppm of each of alcohols, propylene glycol, andcyclohexane. In some embodiments, a device disclosed herein comprisesless than about 10 ppm of each of alcohols, propylene glycol, andcyclohexane. In some embodiments, a device disclosed herein comprisesless than about 5 ppm of each of alcohols, propylene glycol, andcyclohexane. In some embodiments, a device disclosed herein comprisesless than about 1 ppm of each of alcohols, propylene glycol, andcyclohexane.

Further, by way of non-limiting example, the use of the followingcommonly utilized preservatives should be limited, reduced or eliminatedwhen formulating agents for administration to the ear: Benzethoniumchloride, Benzalkonium chloride, and Thiomersal. Thus, in someembodiments, a device disclosed herein is free or substantially free ofbenzethonium chloride, benzalkonium chloride, and thiomersal. In someembodiments, a device disclosed herein comprises less than about 50 ppmof each of benzethonium chloride, benzalkonium chloride, and thiomersal.In some embodiments, a device disclosed herein comprises less than about25 ppm of each of benzethonium chloride, benzalkonium chloride, andthiomersal. In some embodiments, a device disclosed herein comprisesless than about 20 ppm of each of benzethonium chloride, benzalkoniumchloride, and thiomersal. In some embodiments, a device disclosed hereincomprises less than about 10 ppm of each of benzethonium chloride,benzalkonium chloride, and thiomersal. In some embodiments, a devicedisclosed herein comprises less than about 5 ppm of each of benzethoniumchloride, benzalkonium chloride, and thiomersal. In some embodiments, adevice disclosed herein comprises less than about 1 ppm of each ofbenzethonium chloride, benzalkonium chloride, and thiomersal.

Certain antiseptics used to disinfect components of therapeuticpreparations (or the devices utilized to administer the preparations)should be limited, reduced, or eliminated in otic preparations. Forexample, acetic acid, iodine, and merbromin are all known to beototoxic. Additionally, chlorhexidene, a commonly used antiseptic,should be limited, reduced or eliminated to disinfect any component ofan otic preparation (including devices used to administer thepreparation) as it is highly ototoxic in minute concentrations (e.g.,0.05%). Thus, in some embodiments, a device disclosed herein is free orsubstantially free of acetic acid, iodine, merbromin, and chlorhexidene.In some embodiments, a device disclosed herein comprises less than about50 ppm of each of acetic acid, iodine, merbromin, and chlorhexidene. Insome embodiments, a device disclosed herein comprises less than about 25ppm of each of acetic acid, iodine, merbromin, and chlorhexidene. Insome embodiments, a device disclosed herein comprises less than about 20ppm of each of acetic acid, iodine, merbromin, and chlorhexidene. Insome embodiments, a device disclosed herein comprises less than about 10ppm of each of acetic acid, iodine, merbromin, and chlorhexidene. Insome embodiments, a device disclosed herein comprises less than about 5ppm of each of acetic acid, iodine, merbromin, and chlorhexidene. Insome embodiments, a device disclosed herein comprises less than about 1ppm of each of acetic acid, iodine, merbromin, and chlorhexidene.

Further, otic preparations require particularly low concentrations ofseveral potentially-common contaminants that are known to be ototoxic.Other dosage forms, while seeking to limit the contaminationattributable to these compounds, do not require the stringentprecautions that otic preparations require. For example, the followingcontaminants should be absent or nearly absent from otic preparations:arsenic, lead, mercury, and tin. Thus, in some embodiments, a devicedisclosed herein is free or substantially free of arsenic, lead,mercury, and tin. In some embodiments, a device disclosed hereincomprises less than about 50 ppm of each of arsenic, lead, mercury, andtin. In some embodiments, a device disclosed herein comprises less thanabout 25 ppm of each of arsenic, lead, mercury, and tin. In someembodiments, a device disclosed herein comprises less than about 20 ppmof each of arsenic, lead, mercury, and tin. In some embodiments, adevice disclosed herein comprises less than about 10 ppm of each ofarsenic, lead, mercury, and tin. In some embodiments, a device disclosedherein comprises less than about 5 ppm of each of arsenic, lead,mercury, and tin. In some embodiments, a device disclosed hereincomprises less than about 1 ppm of each of arsenic, lead, mercury, andtin.

To prevent ototoxicity, free-radical modulating agent pharmaceuticalcompositions or formulations or devices disclosed herein are optionallytargeted to distinct regions of the targeted auris structures, includingbut not limited to the tympanic cavity, vestibular bony and membranouslabyrinths, cochlear bony and membranous labyrinths and other anatomicalor physiological structures located within the auris interna.

CERTAIN DEFINITIONS

The term “auris-acceptable” with respect to a formulation, compositionor ingredient, as used herein, includes having no persistent detrimentaleffect on the auris interna (or inner ear) of the subject being treated.By “auris-pharmaceutically acceptable,” as used herein, refers to amaterial, such as a carrier or diluent, which does not abrogate thebiological activity or properties of the compound in reference to theauris interna (or inner ear), and is relatively or is reduced intoxicity to the auris interna (or inner ear), i.e., the material isadministered to an individual without causing undesirable biologicaleffects or interacting in a deleterious manner with any of thecomponents of the composition in which it is contained.

As used herein, amelioration or lessening of the symptoms of aparticular otic disease, disorder or condition by administration of aparticular compound or pharmaceutical composition refers to any decreaseof severity, delay in onset, slowing of progression, or shortening ofduration, whether permanent or temporary, lasting or transient that isattributed to or associated with administration of the compound orcomposition.

“Antioxidants” are auris-pharmaceutically acceptable antioxidants, andinclude, for example, butylated hydroxytoluene (BHT), sodium ascorbate,ascorbic acid, sodium metabisulfite and tocopherol. In certainembodiments, antioxidants enhance chemical stability where required.Antioxidants are also used to counteract the ototoxic effects of certaintherapeutic agents, including agents that are used in combination withthe free-radical modulating agents disclosed herein.

“Auris interna” refers to the inner ear, including the cochlea and thevestibular labyrinth, and the round window that connects the cochleawith the middle ear.

“Auris-interna bioavailability” refers to the percentage of theadministered dose of compounds disclosed herein that becomes availablein the inner ear of the animal or human being studied.

“Auris media” refers to the middle ear, including the tympanic cavity,auditory ossicles and oval window, which connects the middle ear withthe inner ear.

“Blood plasma concentration” refers to the concentration of compoundsprovided herein in the plasma component of blood of a subject.

“Carrier materials” are excipients that are compatible with thefree-radical modulating agent, the auris interna and the release profileproperties of the auris-acceptable pharmaceutical formulations. Suchcarrier materials include, e.g., binders, suspending agents,disintegration agents, filling agents, surfactants, solubilizers,stabilizers, lubricants, wetting agents, diluents, and the like.“Auris-pharmaceutically compatible carrier materials” include, but arenot limited to, acacia, gelatin, colloidal silicon dioxide, calciumglycerophosphate, calcium lactate, maltodextrin, glycerine, magnesiumsilicate, polyvinylpyrrolidone (PVP), cholesterol, cholesterol esters,sodium caseinate, soy lecithin, taurocholic acid, phosphatidylcholine,sodium chloride, tricalcium phosphate, dipotassium phosphate, celluloseand cellulose conjugates, sugars sodium stearoyl lactylate, carrageenan,monoglyceride, diglyceride, pregelatinized starch, and the like.

The term “diluent” refers to chemical compounds that are used to dilutethe free-radical modulating agent prior to delivery and which arecompatible with the auris interna.

“Dispersing agents,” and/or “viscosity modulating agents” are materialsthat control the diffusion and homogeneity of the free-radicalmodulating agent through liquid media. Examples of diffusionfacilitators/dispersing agents include but are not limited tohydrophilic polymers, electrolytes, Tween® 60 or 80, PEG,polyvinylpyrrolidone (PVP; commercially known as Plasdone®), and thecarbohydrate-based dispersing agents such as, for example, hydroxypropylcelluloses (e.g., HPC, HPC-SL, and HPC-L), hydroxypropylmethylcelluloses (e.g., HPMC K100, HPMC K4M, HPMC K15M, and HPMC K100M),carboxymethylcellulose sodium, methylcellulose, hydroxyethylcellulose,hydroxypropylcellulose, hydroxypropylmethylcellulose phthalate,hydroxypropylmethylcellulose acetate stearate (HPMCAS), noncrystallinecellulose, magnesium aluminum silicate, triethanolamine, polyvinylalcohol (PVA), vinyl pyrrolidone/vinyl acetate copolymer (S630),4-(1,1,3,3-tetramethylbutyl)-phenol polymer with ethylene oxide andformaldehyde (also known as tyloxapol), poloxamers (e.g., PluronicsF68®, F88®, F127®, and F108®, which are block copolymers of ethyleneoxide and propylene oxide); and poloxamines (e.g., Tetronic 908®, alsoknown as Poloxamine 908®, which is a tetrafunctional block copolymerderived from sequential addition of propylene oxide and ethylene oxideto ethylenediamine (BASF Corporation, Parsippany, N.J.)),polyvinylpyrrolidone K12, polyvinylpyrrolidone K17, polyvinylpyrrolidoneK25, or polyvinylpyrrolidone K30, polyvinylpyrrolidone/vinyl acetatecopolymer (S-630), polyethylene glycol, e.g., the polyethylene glycolhas a molecular weight of about 300 to about 6000, or about 3350 toabout 4000, or about 7000 to about 5400, sodium carboxymethylcellulose,methylcellulose, polysorbate-80, sodium alginate, gums, such as, e.g.,gum tragacanth and gum acacia, guar gum, xanthans, including xanthangum, sugars, cellulosics, such as, sodium carboxymethylcellulose,methylcellulose, sodium carboxymethylcellulose, polysorbate-80, sodiumalginate, polyethoxylated sorbitan monolaurate, polyethoxylated sorbitanmonolaurate, povidone, carbomers, polyvinyl alcohol (PVA), alginates,chitosans and combinations thereof. Plasticizers such as cellulose ortriethyl cellulose are also be used as dispersing agents. Dispersingagents useful in liposomal dispersions and self-emulsifying dispersionsof the free-radical modulating agents disclosed herein are dimyristoylphosphatidyl choline, natural phosphatidyl choline from eggs, naturalphosphatidyl glycerol from eggs, cholesterol and isopropyl myristate.

“Drug absorption” or “absorption” refers to the process of movement ofthe free-radical modulating agents from the localized site ofadministration, by way of example only, the round window membrane of theinner ear, and across a barrier (the round window membranes, asdescribed below) into the auris interna or inner ear structures. Theterms “co-administration” or the like, as used herein, are meant toencompass administration of the free-radical modulating agents to asingle patient, and are intended to include treatment regimens in whichthe free-radical modulating agents are administered by the same ordifferent route of administration or at the same or different time.

The terms “effective amount” or “therapeutically effective amount,” asused herein, refer to a sufficient amount of the free-radical modulatingagent being administered that would be expected to relieve to someextent one or more of the symptoms of the disease or condition beingtreated. For example, the result of administration of the free-radicalmodulating agent disclosed herein is reduction and/or alleviation of thesigns, symptoms, or causes of tinnitus or balance disorders. Forexample, an “effective amount” for therapeutic uses is the amount of afree-radical modulating agent, including a formulation as disclosedherein required to provide a decrease or amelioration in diseasesymptoms without undue adverse side effects. The term “therapeuticallyeffective amount” includes, for example, a prophylactically effectiveamount. For example, an “effective amount” of a modulator of at leastone sirtuin composition disclosed herein is an amount effective toachieve a desired pharmacologic effect or therapeutic improvementwithout undue adverse side effects. It is understood that “an effectiveamount” or “a therapeutically effective amount” varies, in someembodiments, from subject to subject, due to variation in metabolism ofthe compound administered, age, weight, general condition of thesubject, the condition being treated, the severity of the conditionbeing treated, and the judgment of the prescribing physician. It is alsounderstood that “an effective amount” in an extend-release dosing formatmay differ from “an effective amount” in an immediate-release dosingformat based upon pharmacokinetic and pharmacodynamic considerations.

The terms “enhance” or “enhancing” refers to an increase or prolongationof either the potency or duration of a desired effect of a free-radicalmodulating agent, or a diminution of any adverse symptomatology that isconsequent upon the administration of the therapeutic agent. Thus, inregard to enhancing the effect of the free-radical modulating agentsdisclosed herein (e.g., sirtuin modulating agents), the term “enhancing”refers to the ability to increase or prolong, either in potency orduration, the effect of other therapeutic agents that are used incombination with the free-radical modulating agent disclosed herein. An“enhancing-effective amount,” as used herein, refers to an amount of afree-radical modulating agent or other therapeutic agent which isadequate to enhance the effect of another therapeutic agent orfree-radical modulating agent of the target auris structure in a desiredsystem. When used in a patient, amounts effective for this use willdepend on the severity and course of the disease, disorder or condition,previous therapy, the patient's health status and response to the drugs,and the judgment of the treating physician.

The term “inhibiting” includes preventing, slowing, or reversing thedevelopment of a condition, for example, or advancement of a conditionin a patient necessitating treatment.

“Balance disorder” refers to a disorder, illness, or condition whichcauses a subject to feel unsteady, or to have a sensation of movement.Included in this definition are dizziness, vertigo, disequilibrium, andpre-syncope. Diseases which are classified as balance disorders include,but are not limited to, excitotoxicity, benign paroxysmal positionalvertigo, labyrinthitis or the like.

The terms “kit” and “article of manufacture” are used as synonyms.

“Pharmacodynamics” refers to the factors which determine the biologicresponse observed relative to the concentration of drug at the desiredsite within the auris media and/or auris interna.

“Pharmacokinetics” refers to the factors which determine the attainmentand maintenance of the appropriate concentration of drug at the desiredsite within the auris media and/or auris interna.

“Modulator of free-radicals” and “free-radical modulating agent” aresynonyms. They refer to agents that modulate the production of and/ordamage caused by free-radicals, especially reactive oxygen species.

The term “otic intervention” means an external insult or trauma to oneor more auris structures and includes implants, otic surgery,injections, cannulations, or the like. Implants include auris-interna orauris-media medical devices, examples of which include cochlearimplants, hearing sparing devices, hearing-improvement devices,tympanostomy tubes, short electrodes, micro-prostheses or piston-likeprostheses; needles; stem cell transplants; drug delivery devices; anycell-based therapeutic; or the like. Otic surgery includes middle earsurgery, inner ear surgery, typanostomy, cochleostomy, labyrinthotomy,mastoidectomy, stapedectomy, stapedotomy, endolymphatic sacculotomy orthe like. Injections include intratympanic injections, intracochlearinjections, injections across the round window membrane or the like.Cannulations include intratympanic, intracochlear, endolymphatic,perilymphatic or vestibular cannulations or the like.

In prophylactic applications, compositions comprising the free-radicalmodulating agents described herein are administered to a patientsusceptible to or otherwise at risk of a particular disease, disorder orcondition. For example, such conditions include and are not limited toototoxicity, excitotoxicity, sensorineural hearing loss or presbycusis.Such an amount is defined to be a “prophylactically effective amount ordose.” In this use, the precise amounts also depend on the patient'sstate of health, weight, and the like.

As used herein, a “pharmaceutical device” includes any compositiondescribed herein that, upon administration to an ear, provides areservoir for extended release of an active agent described herein.

The term “substantially low degradation products” means less than 5% byweight of the active agent are degradation products of the active agent.In further embodiments, the term means less than 3% by weight of theactive agent are degradation products of the active agent. In yetfurther embodiments, the term means less than 2% by weight of the activeagent are degradation products of the active agent. In furtherembodiments, the term means less than 1% by weight of the active agentare degradation products of the active agent. In some embodiments, anyindividual impurity (e.g., metal impurity, degradation products ofactive agent and/or excipients, or the like) present in a formulationdescribed herein is less than 5%, less than 2%, or less than 1% byweight of the active agent. In some embodiments the formulation does notcontain precipitate during storage or change in color aftermanufacturing and storage.

As used herein “essentially in the form of micronized powder” includes,by way of example only, greater than 70% by weight of the active agentis in the form of micronized particles of the active agent. In furtherembodiments, the term means greater than 80% by weight of the activeagent is in the form of micronized particles of the active agent. In yetfurther embodiments, the term means greater than 90% by weight of theactive agent is in the form of micronized particles of the active agent.

The mean residence time (MRT) is the average time that molecules of anactive agent reside in an otic structure after a dose.

A “prodrug” refers to a free-radical modulator that is converted intothe parent drug in vivo. In certain embodiments, a prodrug isenzymatically metabolized by one or more steps or processes to thebiologically, pharmaceutically or therapeutically active form of thecompound. To produce a prodrug, a pharmaceutically active compound ismodified such that the active compound will be regenerated upon in vivoadministration. In one embodiment, the prodrug is designed to alter themetabolic stability or the transport characteristics of a drug, to maskside effects or toxicity, or to alter other characteristics orproperties of a drug. Compounds provided herein, in some embodiments,are derivatized into suitable prodrugs.

“Solubilizers” refer to auris-acceptable compounds such as triacetin,triethylcitrate, ethyl oleate, ethyl caprylate, sodium lauryl sulfate,sodium doccusate, vitamin E TPGS, dimethylacetamide,N-methylpyrrolidone, N-hydroxyethylpyrrolidone, polyvinylpyrrolidone,hydroxypropylmethyl cellulose, hydroxypropyl cyclodextrins, ethanol,n-butanol, isopropyl alcohol, cholesterol, bile salts, polyethyleneglycol 200-600, glycofurol, transcutol, propylene glycol, and dimethylisosorbide and the like that assist or increase the solubility of thefree-radical modulating agents disclosed herein.

“Stabilizers” refers to compounds such as any antioxidation agents,buffers, acids, preservatives and the like that are compatible with theenvironment of the auris interna. Stabilizers include but are notlimited to agents that will do any of (1) improve the compatibility ofexcipients with a container, or a delivery system, including a syringeor a glass bottle, (2) improve the stability of a component of thecomposition, or (3) improve formulation stability.

“Steady state,” as used herein, is when the amount of drug administeredto the auris interna is equal to the amount of drug eliminated withinone dosing interval resulting in a plateau or constant levels of drugexposure within the targeted structure.

As used herein, the term “subject” is used to mean an animal, preferablya mammal, including a human or non-human. The terms patient and subjectmay be used interchangeably.

“Surfactants” refer to compounds that are auris-acceptable, such assodium lauryl sulfate, sodium docusate, Tween 60 or 80, triacetin,vitamin E TPGS, sorbitan monooleate, polyoxyethylene sorbitanmonooleate, polysorbates, polaxomers, bile salts, glyceryl monostearate,copolymers of ethylene oxide and propylene oxide, e.g., Pluronic®(BASF), and the like. Some other surfactants include polyoxyethylenefatty acid glycerides and vegetable oils, e.g., polyoxyethylene (60)hydrogenated castor oil; and polyoxyethylene alkylethers and alkylphenylethers, e.g., octoxynol 10, octoxynol 40. In some embodiments,surfactants are included to enhance physical stability or for otherpurposes.

The terms “treat,” “treating” or “treatment,” as used herein, includealleviating, abating or ameliorating a disease or condition, for exampletinnitus, symptoms, preventing additional symptoms, ameliorating orpreventing the underlying metabolic causes of symptoms, inhibiting thedisease or condition, e.g., arresting the development of the disease orcondition, relieving the disease or condition, causing regression of thedisease or condition, relieving a condition caused by the disease orcondition, or stopping the symptoms of the disease or condition eitherprophylactically and/or therapeutically.

Other objects, features, and advantages of the methods and compositionsdescribed herein will become apparent from the following detaileddescription. It should be understood, however, that the detaileddescription and the specific examples, while indicating specificembodiments, are given by way of illustration only.

Anatomy of the Ear

As shown in FIG. 4, the outer ear is the external portion of the organand is composed of the pinna (auricle), the auditory canal (externalauditory meatus) and the outward facing portion of the tympanicmembrane, also known as the ear drum. The pinna, which is the fleshypart of the external ear that is visible on the side of the head,collects sound waves and directs them toward the auditory canal. Thus,the function of the outer ear, in part, is to collect and direct soundwaves towards the tympanic membrane and the middle ear.

The middle ear is an air-filled cavity, called the tympanic cavity,behind the tympanic membrane. The tympanic membrane, also known as theear drum, is a thin membrane that separates the external ear from themiddle ear. The middle ear lies within the temporal bone, and includeswithin this space the three ear bones (auditory ossicles): the malleus,the incus and the stapes. The auditory ossicles are linked together viatiny ligaments, which form a bridge across the space of the tympaniccavity. The malleus, which is attached to the tympanic membrane at oneend, is linked to the incus at its anterior end, which in turn is linkedto the stapes. The stapes is attached to the oval window, one of twowindows located within the tympanic cavity. A fibrous tissue layer,known as the annular ligament connects the stapes to the oval window.Sound waves from the outer ear first cause the tympanic membrane tovibrate. The vibration is transmitted across to the cochlea through theauditory ossicles and oval window, which transfers the motion to thefluids in the auris interna. Thus, the auditory ossicles are arranged toprovide a mechanical linkage between the tympanic membrane and the ovalwindow of the fluid-filled auris interna, where sound is transformed andtransduced to the auris interna for further processing. Stiffness,rigidity or loss of movement of the auditory ossicles, tympanic membraneor oval window leads to hearing loss, e.g. otosclerosis, or rigidity ofthe stapes bone.

The tympanic cavity also connects to the throat via the eustachian tube.The eustachian tube provides the ability to equalize the pressurebetween the outside air and the middle ear cavity. The round window, acomponent of the auris interna but which is also accessible within thetympanic cavity, opens into the cochlea of the auris interna. The roundwindow is covered by round window membrane, which consists of threelayers: an external or mucous layer, an intermediate or fibrous layer,and an internal membrane, which communicates directly with the cochlearfluid. The round window, therefore, has direct communication with theauris interna via the internal membrane.

Movements in the oval and round window are interconnected, i.e. as thestapes bone transmits movement from the tympanic membrane to the ovalwindow to move inward against the auris interna fluid, the round window(round window membrane) is correspondingly pushed out and away from thecochlear fluid. This movement of the round window allows movement offluid within the cochlea, which leads in turn to movement of thecochlear inner hair cells, allowing hearing signals to be transduced.Stiffness and rigidity in round window membrane leads to hearing lossbecause of the lack of ability of movement in the cochlear fluid. Recentstudies have focused on implanting mechanical transducers onto the roundwindow, which bypasses the normal conductive pathway through the ovalwindow and provides amplified input into the cochlear chamber.

Auditory signal transduction takes place in the auris interna. Thefluid-filled auris interna, or inner ear, consists of two majorcomponents: the cochlear and the vestibular apparatus. The auris internais located in part within the osseous or bony labyrinth, an intricateseries of passages in the temporal bone of the skull. The vestibularapparatus is the organ of balance and consists of the threesemi-circular canals and the vestibule. The three semi-circular canalsare arranged relative to each other such that movement of the head alongthe three orthogonal planes in space can be detected by the movement ofthe fluid and subsequent signal processing by the sensory organs of thesemi-circular canals, called the crista ampullaris. The cristaampullaris contains hair cells and supporting cells, and is covered by adome-shaped gelatinous mass called the cupula. The hairs of the haircells are embedded in the cupula. The semi-circular canals detectdynamic equilibrium, the equilibrium of rotational or angular movements.

When the head turns rapidly, the semicircular canals move with the head,but endolymph fluid located in the membranous semi-circular canals tendsto remain stationary. The endolymph fluid pushes against the cupula,which tilts to one side. As the cupula tilts, it bends some of the hairson the hair cells of the crista ampullaris, which triggers a sensoryimpulse. Because each semicircular canal is located in a differentplane, the corresponding crista ampullaris of each semi-circular canalresponds differently to the same movement of the head. This creates amosaic of impulses that are transmitted to the central nervous system onthe vestibular branch of the vestibulocochlear nerve. The centralnervous system interprets this information and initiates the appropriateresponses to maintain balance. Of importance in the central nervoussystem is the cerebellum, which mediates the sense of balance andequilibrium.

The vestibule is the central portion of the auris interna and containsmechanoreceptors bearing hair cells that ascertain static equilibrium,or the position of the head relative to gravity. Static equilibriumplays a role when the head is motionless or moving in a straight line.The membranous labyrinth in the vestibule is divided into two sac-likestructures, the utricle and the saccule. Each structure in turn containsa small structure called a macula, which is responsible for maintenanceof static equilibrium. The macula consists of sensory hair cells, whichare embedded in a gelatinous mass (similar to the cupula) that coversthe macula. Grains of calcium carbonate, called otoliths, are embeddedon the surface of the gelatinous layer.

When the head is in an upright position, the hairs are straight alongthe macula. When the head tilts, the gelatinous mass and otoliths tiltscorrespondingly, bending some of the hairs on the hair cells of themacula. This bending action initiates a signal impulse to the centralnervous system, which travels via the vestibular branch of thevestibulocochlear nerve, which in turn relays motor impulses to theappropriate muscles to maintain balance.

The cochlea is the portion of the auris interna related to hearing. Thecochlea is a tapered tube-like structure which is coiled into a shaperesembling a snail. The inside of the cochlea is divided into threeregions, which is further defined by the position of the vestibularmembrane and the basilar membrane. The portion above the vestibularmembrane is the scala vestibuli, which extends from the oval window tothe apex of the cochlea and contains perilymph fluid, an aqueous liquidlow in potassium and high in sodium content. The basilar membranedefines the scala tympani region, which extends from the apex of thecochlea to the round window and also contains perilymph. The basilarmembrane contains thousands of stiff fibers, which gradually increase inlength from the round window to the apex of the cochlea. The fibers ofthe basement membrane vibrate when activated by sound. In between thescala vestibuli and the scala tympani is the cochlear duct, which endsas a closed sac at the apex of the cochlea. The cochlear duct containsendolymph fluid, which is similar to cerebrospinal fluid and is high inpotassium.

The organ of Corti, the sensory organ for hearing, is located on thebasilar membrane and extends upward into the cochlear duct. The organ ofCorti contains hair cells, which have hairlike projections that extendfrom their free surface, and contacts a gelatinous surface called thetectorial membrane. Although hair cells have no axons, they aresurrounded by sensory nerve fibers that form the cochlear branch of thevestibulocochlear nerve (cranial nerve VIII).

As discussed, the oval window, also known as the elliptical windowcommunicates with the stapes to relay sound waves that vibrate from thetympanic membrane. Vibrations transferred to the oval window increasespressure inside the fluid-filled cochlea via the perilymph and scalavestibuli/scala tympani, which in turn causes the round window membraneto expand in response. The concerted inward pressing of the ovalwindow/outward expansion of the round window allows for the movement offluid within the cochlea without a change of intra-cochlear pressure.However, as vibrations travel through the perilymph in the scalavestibuli, they create corresponding oscillations in the vestibularmembrane. These corresponding oscillations travel through the endolymphof the cochlear duct, and transfer to the basilar membrane. When thebasilar membrane oscillates, or moves up and down, the organ of Cortimoves along with it. The hair cell receptors in the Organ of Corti thenmove against the tectorial membrane, causing a mechanical deformation inthe tectorial membrane. This mechanical deformation initiates the nerveimpulse which travels via the vestibulocochlear nerve to the centralnervous system, mechanically transmitting the sound wave received intosignals that are subsequently processed by the central nervous system.

Free Radicals

Free-radicals are highly reactive atoms, molecules, or ions thereactivity of which results from the presence of unpaired electrons.Reactive oxygen species (“ROS”) form as a result of sequential reductionof molecular oxygen. Examples of reactive oxygen species of interest(“ROS”) include, but are not limited to, superoxide, hydrogen peroxide,and hydroxyl radicals. ROS are naturally produced as a by-product of theproduction of ATP. ROS can also result from the use of cisplatin, andaminoglycosides. Further, stress to stereocila caused by acoustic traumaresults in otic hair cells producing ROS.

ROS can damage cells directly by damaging nuclear DNA and mitochondrialDNA. Damage to the former can lead to mutations which impair thefunctioning of cells and/or apoptosis. Damage to the latter oftenresults in decreased energy production and increased ROS production bothof which can lead to impaired cellular functioning or cell death.Further, ROS can also damage or kill cells by oxidizing thepolydesaturated fatty acids which comprise lipids, oxidizing the aminoacids which comprise proteins, and oxidizing co-factors necessary forthe activity of enzymes. Antioxidants can ameliorate damage by caused byROS by preventing their formation, or scavenging the ROS before they candamage the cell.

Damage to mitochondria by ROS is often seen in hearing loss, especiallyhearing loss due to aging. The loss of ATP correlates to a loss inneural functioning in the inner ear. It can also lead to physiologicalchanges in the inner ear. Further, damage to mitochondria often resultsin an increased rate of cellular degradation and/or cell death of innerear cells. The cells of the stria vascularis are the most metabolicallyactive due to the vast energy requirements needed to maintain the ionicbalance of fluids in the inner ear. Thus, the cells of the striavascularis are most often damaged or killed due to damage of themitochondria.

Diseases

Otic disorders, including auris interna, auris media, and auris externadisorders, produce symptoms which include but are not limited to hearingloss, nystagmus, vertigo, tinnitus, swelling, and congestion. Thesedisorders may have many causes, such as oxidative damage caused byreactive oxygen species and adverse response to drugs or other chemicalagents.

Excitotoxicity

Excitotoxicity refers to the death or damaging of neurons and/or otichair cells by glutamate and/or similar substances.

Glutamate is the most abundant excitatory neurotransmitter in thecentral nervous system. Pre-synaptic neurons release glutamate uponstimulation. It flows across the synapse, binds to receptors located onpost-synaptic neurons, and activates these neurons. The glutamatereceptors include the NMDA, AMPA, and kainate receptors. Glutamatetransporters are tasked with removing extracellular glutamate from thesynapse. Certain events (e.g. ischemia or stroke) can damage thetransporters. This results in excess glutamate accumulating in thesynapse. Excess glutamate in synapses results in the over-activation ofthe glutamate receptors.

The AMPA receptor is activated by the binding of both glutamate andAMPA. Activation of certain isoforms of the AMPA receptor results in theopening of ion channels located in the plasma membrane of the neuron.When the channels open, Na⁺ and Ca²⁺ ions flow into the neuron and K⁺ions flow out of the neuron.

The NMDA receptor is activated by the binding of both glutamate andNMDA. Activation of the NMDA receptor, results in the opening of ionchannels located in the plasma membrane of the neuron. However, thesechannels are blocked by Mg²⁺ ions. Activation of the AMPA receptorresults in the expulsion of Mg²⁺ ions from the ion channels into thesynapse. When the ion channels open, and the Mg²⁺ ions evacuate the ionchannels, Na⁺ and Ca²⁺ ions flow into the neuron, and K⁺ ions flow outof the neuron.

Excitotoxicity occurs when the NMDA receptor and AMPA receptors areover-activated by the binding of excessive amounts of ligands, forexample, abnormal amounts of glutamate. The over-activation of thesereceptors causes excessive opening of the ion channels under theircontrol. This allows abnormally high levels of Ca²⁺ and Na⁺ to enter theneuron. The influx of these levels of Ca²⁺ and Na⁺ into the neuroncauses the neuron to fire more often. This increased firing yields arapid buildup of free-radicals and inflammatory compounds. Thefree-radicals damage the mitochondria, depleting the cell's energystores. Further, excess levels of Ca²⁺ and Na⁺ ions activate excesslevels of enzymes including, but not limited to, phospholipases,endonucleases, and proteases. The over-activation of these enzymesresults in damage to the cytoskeleton, plasma membrane, mitochondria,and DNA of the neuron.

Ototoxicity

Ototoxicity refers to hearing loss caused by a toxin. The hearing lossmay be due to trauma to otic hair cells, the cochlea, and/or the VIInerve. Multiple drugs are known to be ototoxic. Often ototoxicity isdose-dependent. It may be permanent or reversible upon withdrawal of thedrug.

Known ototoxic drugs include, but are not limited to, the aminoglycosideclass of antibiotics (e.g. gentamicin, and amikacin), some members ofthe macrolide class of antibiotics (e.g erythromycin), some members ofthe glycopeptide class of antibiotics (e.g. gentamicin), salicylic acid,nicotine, some chemotherapeutic agents (e.g. actinomycin, bleomycin,cisplatin, carboplatin and vincristine), and some members of the loopdiuretic family of drugs (e.g. furosemide).

Cisplatin and the aminoglycoside class of antibiotics induce theproduction of ROS. Both cisplatin and the aminoglycoside class ofantibiotics are also thought to damage the ear by binding melanin in thestria vascularis of the inner ear.

Salicylic acid is classified as ototoxic as it inhibits the function ofthe protein prestin. Prestin mediates outer otic hair cell motility bycontrolling the exchange of chloride and carbonate across the plasmamembrane of outer otic hair cells. It is only found in the outer otichair cells, not the inner otic hair cells.

Otic and/or vestibular disorders, including auris interna and aurismedia disorders, produce symptoms which include but are not limited tohearing loss, nystagmus, vertigo, tinnitus, inflammation, swelling,infection and congestion. These disorders may have many causes, such asinfection, injury, inflammation, tumors and adverse response to drugs orother chemical agents.

Sensorineural Hearing Loss

Sensorineural hearing loss is a type of hearing loss in which resultsfrom defects (congenital and acquired) in the vestibulocochlear nerve(also known as the cranial nerve VIII), or the inner ear. With regardsto defects of the inner ear, the majority of these defects are defectsof otic hair cells.

Aplasia of the cochlea, chromosomal defects, and congenitalcholesteatoma are examples of the congenital defects which can result insensorineural hearing loss. By way of non-limiting example, inflammatorydiseases (e.g. suppurative labyrinthitis, meningitis, mumps, measles,viral syphilis, and autoimmune disorders), Meniere's Disease, exposureto ototoxic drugs (e.g. aminoglycosides, loop diuretics,antimetabolites, salicylates, and cisplatin), physical trauma,presbyacusis, and acoustic trauma (prolonged exposure to sound in excessof 90 dB) can all result in acquired sensorineural hearing loss. Withregards to acoustic trauma, the damage to neurons and hair cells resultsin part from the generation of ROS.

Presbycusis

Presbycusis (or presbyacusis) is the progressive bilateral loss ofhearing that results from aging. Most hearing loss occurs at higherfrequencies (i.e. frequencies above 15 or 16 Hz) making it difficult tohear a female voice (as opposed to male voice), and an inability todifferentiate between high-pitched sounds (such as “s” and “th”). It maybe difficult filter out background noise. The disorder is most oftentreated by the implantation of a hearing aid and/or the administrationof pharmaceutical agents which prevent the build up of ROS.

The disorder is caused by changes in the physiology of the inner ear,the middle ear, and/or the VII nerve. Changes in the inner ear resultingin presbycusis include epithelial atrophy with loss of otic hair cellsand/or stereocilia, atrophy of nerve cells, atrophy of the striavascularis, and the thickening/stiffening of the basilar membrane.Additional changes which can contribute to presbycusis include theaccumulation of defects in the tympanic membrane and the ossicles.

Changes leading to presbycusis can occur due to the accumulation ofmutations in DNA, and mutations in mitochondrial DNA; however, thechanges may be exacerbated by exposure to loud noise, exposure toototoxic agents, infections, and/or the lessening of blood flow to theear. The latter is attributable to atherosclerosis, diabetes,hypertension, and smoking.

Pharmaceutical Agents

Provided herein are free-radical modulating compositions or formulationsthat ameliorate damage to and/or the degeneration of the neurons and/orhair cells of the auris. Further provided herein are free-radicalmodulating compositions or formulations that prevent oxidative damage tothe neurons and/or hair cells of the auris. Otic and vestibulardisorders, have causes and symptoms that are responsive to thepharmaceutical agents disclosed herein, or other pharmaceutical agents.Free-radical modulating agents which are not disclosed herein but whichare useful for the amelioration or eradication of otic and/or vestibulardisorders are expressly included and intended within the scope of theembodiments presented.

Moreover, pharmaceutical agents which have been previously shown to betoxic, harmful or non-effective during systemic or localized applicationin other organ systems, for example through toxic metabolites formedafter hepatic processing, toxicity of the drug in particular organs,tissues or systems, through high levels needed to achieve efficacy,through the inability to be released through systemic pathways orthrough poor pK characteristics, are useful in some embodiments herein.Accordingly, pharmaceutical agents which have limited or no systemicrelease, systemic toxicity, poor pK characteristics or combinationsthereof are contemplated within the scope of the embodiments disclosedherein.

The free-radical modulating formulations disclosed herein are optionallytargeted directly to otic structures where treatment is needed; forexample, one embodiment contemplated is the direct application of thefree-radical modulating formulations disclosed herein onto the roundwindow membrane or the crista fenestrae cochlea of the auris interna,allowing direct access and treatment of the auris interna, or inner earcomponents. In other embodiments, the free-radical modulatingformulation disclosed herein is applied directly to the oval window. Inyet other embodiments, direct access is obtained through microinjectiondirectly into the auris interna, for example, through cochlearmicroperfusion. Such embodiments also optionally comprise a drugdelivery device, wherein the drug delivery device delivers thefree-radical modulating formulations through use of a needle andsyringe, a pump, a microinjection device, an in situ forming spongymaterial or any combination thereof.

Optionally, a controlled release free-radical modulating formulationincludes otoprotective agents, such as antioxidants, alpha lipoic acid,calcium, fosfomycin or iron chelators, to counteract potential ototoxiceffects that may arise from the use of specific therapeutic agents orexcipients, diluents or carriers.

Antioxidants

Contemplated for use with the formulations disclosed herein are agentsthat relieve, prevent, reverse or ameliorate the degeneration of neuronsand/or hair cells of the auris due to free-radicals or the dysfunctionof the mitochondria. Accordingly, some embodiments incorporate the useof agents which prevent and/or ameliorate the damage caused byfree-radicals. In some embodiments, the agents which prevent and/orameliorate the damage caused by free-radicals is an antioxidant.

In some embodiments, the antioxidant is N-acetylcysteine; vitamin E(tocopherols and tocotrienols); vitamin C; vitamin A; lutein; seleniumglutathione; melatonin; a polyphenol; a carotenoid (e.g. lycopene,carotenes); coenzyme Q-10; Ebselen(2-phenyl-1,2-benzisoselenazol-3(2H)-one (also called PZ 51 or DR3305);L-methionine; azulenyl nitrones (e.g. stilbazulenyl nitrone);L-(+)-Ergothioneine((S)-a-Carboxy-2,3-dihydro-N,N,N-trimethyl-2-thioxo-1H-imidazole4-ethanaminiuminner salt); Caffeic Acid Phenyl Ester (CAPE); dimethylthiourea;dimethylsulfoxide; disufenton sodium (NXY-059; disodium4-[(Z)-(tert-butyl-oxidoazaniumylidene)methyl]benzene-1,3-disulfonate);pentoxifylline; MCI-186 (3-Methyl-1-phenyl-2-pyrazolin-5-one); Ambroxol(trans-4-(2-Amino-3,5-dibromobenzylamino)cyclohexane-HCl; U-83836E((−)-2-((4-(2,6-di-1-Pyrrolidinyl-4-pyrimidinyl)-1-piperzainyl)methyl)-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran-6-ol2HCl);MITOQ (mitoquinone mesylate, Antipodean Pharmaceuticals); Idebenone(2-(10-hydroxydecyl)-5,6-dimethoxy-3-methyl-cyclohexa-2,5-diene-1,4-dione);(+)-cyanidanol-3; superoxide dismutases, catalases, peroxiredixons,resveratrol, flavonoids or combinations thereof.

Iron Chelators

Contemplated for use with the formulations disclosed herein are agentsthat relieve, prevent, reverse or ameliorate the degeneration of neuronsand/or hair cells of the auris due to free-radicals or the dysfunctionof the mitochondria. Accordingly, some embodiments incorporate the useof agents which prevent and/or ameliorate the damage caused byfree-radicals. In some embodiments, the agents which prevent and/orameliorate the damage caused by free-radicals is an iron chelator. Theiron chelator, deferoxamine, prevents ototoxic damage to the earresulting from treatment with neomycin when it is co-administered withneomycin.

In some embodiments, the iron chelator is desferrioxamine (DFO);hydroxybenzyl ethylene diamine; fullerenol-1, pyrrolidinedithiocarbamate; desferal; Vk-28 (5-[4-(2-hydroxyethyl)piperazine-1-ylmethyl]-quinoline-8-ol); EDTA or salts thereof, citricacid or salts thereof, clioquinol; echinochrome; PIH (pyridoxalisonicotinoyl hydrazone); deferasirox; HBED (N,N′-bis(2-hydroxybenzyl)ethylenediamine-N,N′-diacetic acid); SIH (salicylaldehyde isonicotinoylhydrazone); deferiprone; L1 (1,2-dimethyl-3-hydroxy-4-pyridone); Kojicacid (5-hydroxy-2-hydroxymethyl-4-pyrone); deferoxamine;2,3-dihydroxybenzoate; or combinations thereof.

N-κB Modulators

In certain instances, a member of the NF-κB family is activated inresponse to (amongst other triggers) cytokines, LPS, UV radiation, shock(e.g. heat, or osmotic), oxidative stress, or combinations thereof. Incertain instances, exposure to oxidation leads to the phosphorylation ofan IkB by IKK. In certain instances, the phosphorylation of an IkB byIKK leads to the proteolytic degradation of IkB. In certain instances,the degradation of an IkB allows NF-kB to translocate to the nucleuswhere it binds to kB enhancer elements of target genes and inducestranscription. In certain instances, an active NF-κB transcriptionfactor inhibits oxidation and cell damage.

Accordingly, some embodiments incorporate the use of agents thatmodulate an NF-kB transcription factor. In certain instances, the agentthat modulates an NF-kN transcription factor is an antagonist, partialagonist, inverse agonist, neutral or competitive antagonist, allostericantagonist, and/or orthosteric antagonist of NF-kB. In some embodiments,the agent that modulates an NF-kB transcription factor is an NF-kBtranscription factor agonist, partial agonist, and/or positiveallosteric modulator. In some embodiments, the NF-kB transcriptionfactor agonist, partial agonist, and/or positive allosteric modulator isPam₃Cys((S)-(2,3-bis(palmitoyloxy)-(2RS)-propyl)-N-palmitoyl-(R)-Cys-(S)-Ser(S)-Lys4-OH,trihydrochloride); Act1 (NF-kB activator 1); or combinations thereof.

In some embodiments, the NF-kB agonist, partial agonist, and/or positiveallosteric modulator is an IkB antagonist, partial agonist, inverseagonist, neutral or competitive antagonist, allosteric antagonist,and/or orthosteric antagonist. In some embodiments, the IkB antagonist,partial agonist, inverse agonist, neutral or competitive antagonist,allosteric antagonist, and/or orthosteric antagonist is an anti-IkBantibody.

In some embodiments, the agent that modulates an NF-kB transcriptionfactor is an NF-kB transcription factor antagonist, partial agonist,inverse agonist, neutral or competitive antagonist, allostericantagonist, and/or orthosteric antagonist. In some embodiments, theNF-kB transcription factor antagonist, partial agonist, inverse agonist,neutral or competitive antagonist, allosteric antagonist, and/ororthosteric antagonist is Acetyl-11-keto-b-Boswellic Acid;Andrographolide; Caffeic Acid Phenethyl Ester (CAPE); Gliotoxin;Isohelenin; NEMO-Binding Domain Binding Peptide(DRQIKIWFQNRRMKWKKTALDWSWLQTE); NF-kB Activation Inhibitor(6-Amino-4-(4-phenoxyphenylethylamino)quinazoline); NF-kB ActivationInhibitor II (4-Methyl-N1-(3-phenylpropyl)benzene-1,2-diamine); NF-kBActivation Inhibitor III(3-Chloro-4-nitro-N-(5-nitro-2-thiazolyl)-benzamide); NF-kB ActivationInhibitor IV ((E)-2-Fluoro-4′-methoxystilbene); NF-kB ActivationInhibitor V (5-Hydroxy-(2,6-diisopropylphenyl)-1H-isoindole-1,3-dione);NF-kB SN50 (AAVALLPAVLLALLAPVQRKRQKLMP); Oridonin; Parthenolide; PPM-18(2-Benzoylamino-1,4-naphthoquinone); Ro106-9920; Sulfasalazine; TIRAPInhibitor Peptide (RQIKIWFNRRMKWKKLQLRDAAPGGAIVS); Withaferin A;Wogonin; or combinations thereof.

In some embodiments, the agent that modulates an NF-kB transcriptionfactor inhibits NF-kB activation by TNF. In some embodiments, the agentthat modulates an NF-kB transcription factor is an antagonist, partialagonist, inverse agonist, neutral or competitive antagonist, allostericantagonist, and/or orthosteric antagonist of TNF. In some embodiments,the agent that inhibits NF-kB activation by TNF is BAY 11-7082((E)3-[(4-Methylphenyl)sulfonyl]-2-propenenitrile); BAY 11-7085((E)3-[(4-t-Butylphenyl)sulfonyl]-2-propenenitrile); (E)-Capsaicin; orcombinations thereof.

In some embodiments, the agent that modulates an NF-kB transcriptionfactor is an IKK antagonist, partial agonist, inverse agonist, neutralor competitive antagonist, allosteric antagonist, and/or orthostericantagonist. In some embodiments, the IKK antagonist, partial agonist,inverse agonist, neutral or competitive antagonist, allostericantagonist, and/or orthosteric antagonist is Aurothiomalate (ATM orAuTM); Evodiamine; Hypoestoxide; IKK Inhibitor III (BMS-345541); IKKInhibitor VII; IKK Inhibitor X; IKK Inhibitor II; IKK-2 Inhibitor IV;IKK-2 Inhibitor V; IKK-2 Inhibitor VI; IKK-2 Inhibitor (SC-514); IkBKinase Inhibitor Peptide; IKK-3 Inhibitor IX; or combinations thereof.

In some embodiments, the NF-kB antagonist, partial agonist, inverseagonist, neutral or competitive antagonist, allosteric antagonist,and/or orthosteric antagonist is an IKK agonist, partial agonist, and/orpositive allosteric modulator.

Mitochondrial Modulators

Contemplated for use with the formulations disclosed herein are agentsthat relieve, prevent, reverse or ameliorate the degeneration of neuronsand/or hair cells of the auris due to free-radicals or the dysfunctionof the mitochondria. Accordingly, some embodiments incorporate the useof one or more agents that modulate the activity of the mitochondria. Insome embodiments, the agent which modulates the activity of themitochondria is acetylcarnitine; lipoic acid; or combinations thereof.In some embodiments, a modulator of coenzyme Q 10 is a modulator ofmitochondrial function.

Nitric Oxide Synthase Modulators

Contemplated for use with the compositions disclosed herein are agentsfor treating or ameliorating hearing loss or reduction resulting fromdestroyed, stunted, malfunctioning, damaged, fragile or missing hairs inthe inner ear. Nitric oxide (NO) is a neurotransmitter. It issynthesized by multiple nitric oxide synthases (NOS) from arginine andoxygen. It is also derived from the reduction of inorganic nitrate. Incertain instances, it induces vasodilation; thus, increasing blood flow.In certain instances, it increases cochlear blood flow. In certaininstances, NO damages blood vessel walls. In certain instances, NOameliorates vascular protein leakage in the cochlea. In certaininstances, NO increases the sensitivity of hair cells. In certaininstances, NO reacts with super-oxide to form the free-radicalperoxynitrite. Accordingly, some embodiments incorporate the use ofagents that modulate nitric oxide and/or nitric oxide synthase (NOS)and/or inducible NOS (iNOS).

In some embodiments, the agent that modulates NO and/or NOS is anantagonist of NO or NOS. In some embodiments, the agent that modulatesNO and/or NOS modulates the activity of inducible NOS (iNOS) that isreleased in the presence of free radicals. In some instances, inductionof high-output iNOS occurs in an oxidative environment, and high levelsof NO react with superoxide leading to peroxynitrite formation and celltoxicity. In some embodiments, the antagonist of NO and/or NOS isaminoguanidine; 1-Amino-2-hydroxyguanidine p-toluensulfate; GED(guanidinoethyldisulfide); bromocriptine mesylate; idebenone; SDMA(symmetric N^(G),N^(G)-Dimethyl-L-arginine); ADMA (asymmetricN^(G),N^(G)-Dimethyl-L-arginine); L-NMMA (N^(G)-monomethyl-L-arginine);L-NMEA (N^(G)-monoethyl-L-arginine); D-MMA(N^(G)-monomethyl-D-arginine); L-NIL (N⁶-(1-Iminoethyl)-L-lysinehydrochloride); L-NNA (N^(G)-nitro-L-arginine); L-NPA(N^(G)-propyl-L-arginine); L-NAME (N^(G)-nitro-L-arginine methyl esterdihydrochloride); L-VNIO (N5-(1-imino-3-butenyl)-1-ornithine);diphenyleneiodonium chloride; 2-ethyl-2-thiopseudourea; haloperidol;L-NIO (L-N⁵-(1-iminoethyl)ornithine); MEG (methylecgonidine); SMT(S-methylisothiourea sulfate); SMTC (S-methyl-L-thiocitrulline); 7-Ni(7-nitroindazole); nNOS inhibitor I((4S)-N-(4-Amino-[aminoethyl]aminopentyl)-N′-nitroguanidine); 1,3-PBITU(S,S′-1,3-Phenylene-bis(1,2-ethanediyl)-bis-isothiourea);L-thiocitrulline; TRIM (1-(2-trifluoromethylphenyl)imidazole); MTR-105(S-ethylisothiuronium diethylphosphate); BBS-1; BBS-2; ONO-1714((1S,5S,6R,7R)-7-chloro-3-amino-5-methyl-2-azabicyclo[4.1.0]heptanehydrochloride); GW273629(3-[[2-[(1-iminoethyl)amino]ethyl]sulphonyl]-L-alanine); GW 274150((S)-2-amino-(1-iminoethylamino)-5-thioheptanoic acid); PPA250(3-(2,4-difluorophenyl)-6-{2-[4-(1H-imidazol-1-ylmethyl)phenoxy]ethoxy}-2-phenylpyridine); AR-R17477([N-(4-(2-((3-chlorophenylmethyl)amino)ethyl)phenyl)-2-thiophecarboxamidinedihydrochloride); AR-R18512(N(2-methyl-1,2,3,4-tetrahydroisoquinoline-7-yl)-2-thiophenecarboximidamide);spiroquinazolone; 1400W(N-[[3-(aminomethyl)phenyl]methyl]-ethanimidamide dihydrochloride); orcombinations thereof.

In some embodiments, the agent that modulates NO and/or NOS is anagonist of NO and/or NOS, or a donor of NO. In some embodiments, theagonist of NO and/or NOS, or donor of NO, is S-NC (S-nitrosocysteine);NTG (nitroglycerine); SNP (sodium nitroprusside); thapsigargin; vascularendothelial growth factor (VEGF); bradykinin; ATP;sphingosine-1-phosphate; estrogen; angiopoietin; acetylcholine; SIN-1(3-morpholinosydnonimine); GEA 3162 (1,2,3,4-oxatriazolium,5-amino-3-(3,4-dichlorophenyl)-,chloride); GEA 3175(3-(3-chloro-2-methylphenyl)-5-[[4-methylphenyl)sulphonyl]amino]-)hydroxide);GEA 5024(1,2,3,4-oxatriazolium,5-amino-3-(30chloro-2-methyl-phenyl)chloride);GEA 5538(,2,3,4-Oxatriazolium,3-(3-chloro-2-methylphenyl)-5-[[[cyanomethylamino]carbonyl]amino]-hydroxideinner salt); SNAP (S-nitroso-N-acetylpenicillamine); molsidomine; CNO-4(1-[(4′,5′-Bis(carboxymethoxy)-2′-nitrophenyl)methoxy]-2-oxo-3,3,diethyl-1-triazenedipotassium salt); CNO-5([1-(4′,5′-Bis(carboymethoxy)-2′-nitrophenyl)methoxy]-2-oxo-3,3-diethyl-1-triazinediacetoxymethyl ester); DEA/NO, IPA/NO, SPER/NO, SULFI/NO, OXI/NO,DETA/NO; or combinations thereof.

Inhibitors of the MAPK/JNK Signaling Cascade

Contemplated for use with the formulations disclosed herein are agentsthat protect neurons and otic hair cells from oxidative damage. Cellularstress (e.g. acoustic trauma, oxidative stress, exposure to an ototoxicagent, etc.) activates the mitogen-activated protein kinases (MAPK).

Accordingly, some embodiments incorporate the use of agents whichmodulate the activity of the MAPK/JNK signaling cascade. In someembodiments, the agent is an antagonist, partial agonist, inverseagonist, neutral or competitive antagonist, allosteric antagonist,and/or orthosteric antagonist of a MAP/JNK signaling target. In someembodiments, the agent which antagonizes the MAPK/JNK signaling cascadeis minocycline; SB-203580 (4-(4-Fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole); PD 169316(4-(4-Fluorophenyl)-2-(4-nitrophenyl)-5-(4-pyridyl)-1H-imidazole); SB202190(4-(4-Fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)1H-imidazole); RWJ67657(4-[4-(4-fluorophenyl)-1-(3-phenylpropyl)-5-(4-pyridinyl)-1H-imidazol-2-yl]-3-butyn-1-ol);SB 220025(5-(2-Amino-4-pyrimidinyl)-4-(4-fluorophenyl)-1-(4-piperidinlyl)imidazole);or combinations thereof. Minocycline prevents the apoptosis of otic haircells following treatment with the ototoxic antibiotic gentamicin byinhibiting the induction of p38 MAPK phosphorylation. In someembodiments, the agent which antagonizes the MAPK/JNK signaling cascadeis D-JNKI-1 ((D)-hJIP₁₇₅₋₁₅₇-DPro-DPro-(D)-HIV-TAT₅₇₋₄₈), SP600125(anthra[1,9-cd]pyrazol-6(2H)-one), JNK Inhibitor I((L)-HIV-TAT₄₈₋₅₇-PP-JBD₂₀), JNK Inhibitor III((L)-HIV-TAT₄₇₋₅₇-gaba-c-Junδ₃₃₋₅₇), AS601245 (1,3-benzothiazol-2-yl(2-[[2-(3-pyridinyl)ethyl]amino]-4 pyrimidinyl)acetonitrile), JNKInhibitor VI (H₂N-RPKRPTTLNLF-NH₂), JNK Inhibitor VIII(N-(4-Amino-5-cyano-6-ethoxypyridin-2-yl)-2-(2,5-dimethoxyphenyl)acetamide),JNK Inhibitor IX(N-(3-Cyano-4,5,6,7-tetrahydro-1-benzothien-2-yl)-1-naphthamide),dicumarol (3,3′-Methylenebis(4-hydroxycoumarin)), SC-236(4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzene-sulfonamide),CEP-1347 (Cephalon), CEP-11004 (Cephalon); or combinations thereof.

Sirtuin Modulators

The sirtuins (or Sir2 proteins) comprise class III of the histonedeacetylases (HDACs). While they are classified as protein deacetylasessome also function as mono-ADP-ribosyltransferases. Each sirtuin proteinhas a homologous core sequence of 250 amino acids. This sequence ishighly conserved over multiple species. Further, in order to catalyzethe deacetylation of a protein, each sirtuin requires NAD⁺ as acofactor. There are seven members of the family: Sirt1, Sirt2, Sirt3,Sirt4, Sirt5, Sirt6, and Sirt7. Sirt1 and Sirt3 are proteindeacetylases. Sirt2 is involved in mitosis.

Agonism of Sirt1 yields multiple benefits which have previously beenidentified in subjects undergoing caloric restriction. These benefitsinclude, but are not limited to, decreased glucose levels and improvedinsulin sensitivity, increased mitochondrial activity, and decreasedadiposity (due to the Sirt1 mediated repression of PPAR-γ). Decreases inglucose levels and adiposity can contribute to the amelioration ofpresbycusis as diabetes and atherosclerosis are both factors whichcontribute to the development and progression of presbycusis.

Sirt1 can prevent apoptosis by deacetylating the pro-apoptotic genes p53and Ku-70. Additional substrates for Sirt1 include, but are not limitedto, the transcription factors NFκB, Fox01, Fox03a, Fox04, Fox05; thetranscription repressor Hic1; and Pgc-1α, which regulates, among othercellular functions, adaptive thermogenesis, glucose metabolism, andtriglyceride metabolism. Agonism of Sirt3 results in increased cellularrespiration and a decrease in the production of reactive oxygen species(ROS).

The catalysis of deacetylation by sirtuins is NAD⁺ (nicotinamide adeninedinucleotide) dependent. Upon binding to an acetylated protein, thesirtuin hydrolyzes NAD⁺ by breaking the glycosidic bond betweennicotinamide and ADP-ribose. The acetyl group of the acetylated proteinis then transferred to ADP-ribose. At the completion of the reactionnicotinamide, the deacetylated protein, and 2′-O-acetyl-ADP-ribose arereleased.

Multiple compounds modulate the sirtuin catalyzed deacetylation ofproteins. Administration of certain polyphenols such as, but not limitedto, stilbenes, chalcones, flavones, isoflavones, flavanones,anthocyanidins, catechins, results in the decrease of the K_(m) of thedeacetylation reaction. Further, as free nicotinamide antagonizes thedeacetylation reaction, compounds which inhibit the binding ofnicotinamide to sirtuins will also agonize the activity of sirtuins.

Administration of the sirtuin agonizing agent resveratrol(trans-3,5,4′-trihydroxystilbene) decreases apoptosis. It also increasesglutamate uptake and thus ameliorates excitotoxicity. Further,administration of resveratrol results in lower levels of reactive oxygenspecies (ROS) and thus ameliorates damage caused by ischemia,excitotoxicity, ototoxicity caused by cisplatin and aminoglycosides,acoustic trauma and presbycusis.

Contemplated for use with the formulations disclosed herein are agentsthat relieve, prevent, reverse or ameliorate the degeneration of neuronsand/or hair cells of the auris due to free-radicals or the dysfunctionof the mitochondria. Accordingly, some embodiments incorporate the useof one or more agents the modulate sirtuin catalyzed deacetylationreactions. In some embodiments, the agent which modulates sirtuincatalyzed deacetylation reactions is a stilbene. In some embodiments,the stilbene is trans-stilbene, cis-stilbene, resveratrol, piceatannol,rhapontin, deoxyrhapontin, butein, or combinations thereof.

In some embodiments, the stilbene is resveratrol. In some embodiments,the stilbene is an analog of resveratrol. In some embodiments, theanalog of resveratrol is SRT-501 (RM-1821). For additional analogs ofresveratrol see U.S. Patent App. Pub. No. 2006/0276393, which is herebyincorporated by reference for this disclosure.

Contemplated for use with the formulations disclosed herein are agentsthat relieve, prevent, reverse or ameliorate the degeneration of neuronsand/or hair cells of the auris due to free-radicals or the dysfunctionof the mitochondria. Accordingly, some embodiments incorporate the useof one or more agents the modulate sirtuin catalyzed deacetylationreactions. In some embodiments, the agent which modulates sirtuincatalyzed deacetylation reactions is a chalcone. In some embodiments,the chalcone is chalcon; isoliquirtigen; butein;4,2′,4′-trihydroxychalcone; 3,4,2′,4′,6′-pentahydroxychalcone; orcombinations thereof.

Contemplated for use with the formulations disclosed herein are agentsthat relieve, prevent, reverse or ameliorate the degeneration of neuronsand/or hair cells of the auris due to free-radicals or the dysfunctionof the mitochondria. Accordingly, some embodiments incorporate the useof one or more agents the modulate sirtuin catalyzed deacetylationreactions. In some embodiments, the agent which modulates sirtuincatalyzed deacetylation reactions is a flavone. In some embodiments, theflavone is flavone, morin, fisetin; luteolin; quercetin; kaempferol;apigenin; gossypetin; myricetin; 6-hydroxyapigenin; 5-hydroxyflavone;5,7,3′,4′,5′-pentahydroxyflavone; 3,7,3′,4′,5′-pentahydroxyflavone;3,6,3′,4′-tetrahydroxyflavone; 7,3′,4′,5′-tetrahydroxyflavone;3,6,2′,4′-tetrahydroxyflavone; 7,4′-dihydroxyflavone;7,8,3′,4′-tetrahydroxyflavone; 3,6,2′,3′-tetrahydroxyflavone;4′-hydroxyflavone; 5-hydroxyflavone; 5,4′-dihydroxyflavone;5,7-dihydroxyflavone; or combinations thereof.

Contemplated for use with the formulations disclosed herein are agentsthat relieve, prevent, reverse or ameliorate the degeneration of neuronsand/or hair cells of the auris due to free-radicals or the dysfunctionof the mitochondria. Accordingly, some embodiments incorporate the useof one or more agents the modulate sirtuin catalyzed deacetylationreactions. In some embodiments, the agent which modulates sirtuincatalyzed deacetylation reactions is an isoflavone. In some embodiments,the isoflavone is daidzein, genistein, or combinations thereof.

Contemplated for use with the formulations disclosed herein are agentsthat relieve, prevent, reverse or ameliorate the degeneration of neuronsand/or hair cells of the auris due to free-radicals or the dysfunctionof the mitochondria. Accordingly, some embodiments incorporate the useof one or more agents the modulate sirtuin catalyzed deacetylationreactions. In some embodiments, the agent which modulates sirtuincatalyzed deacetylation reactions is a flavanone. In some embodiments,the flavanone is naringenin; flavanone;3,5,7,3′,4′-pentahydroxyflavanone; or combinations thereof.

Contemplated for use with the formulations disclosed herein are agentsthat relieve, prevent, reverse or ameliorate the degeneration of neuronsand/or hair cells of the auris due to free-radicals or the dysfunctionof the mitochondria. Accordingly, some embodiments incorporate the useof one or more agents the modulate sirtuin catalyzed deacetylationreactions. In some embodiments, the agent which modulates sirtuincatalyzed deacetylation reactions is an anthocyanidin. In someembodiments, the anthocyanidin is pelargonidin chloride, cyanidinchloride, delphinidin chloride, or combinations thereof.

Contemplated for use with the formulations disclosed herein are agentsthat relieve, prevent, reverse or ameliorate the degeneration of neuronsand/or hair cells of the auris due to free-radicals or the dysfunctionof the mitochondria. Accordingly, some embodiments incorporate the useof one or more agents the modulate sirtuin catalyzed deacetylationreactions. In some embodiments, the agent which modulates sirtuincatalyzed deacetylation reactions is a catechin. In some embodiments,the catechin is (−)-epicatechin (Hydroxy Sites: 3,5,7,3′,4′);(−)-catechin (Hydroxy Sites: 3,5,7,3′,4′); (−)-gallocatechin (HydroxySites: 3,5,7,3′,4′,5′) (+)-catechin (Hydroxy Sites: 3,5,7,3′,4′);(+)-epicatechin (Hydroxy Sites: 3,5,7,3′,4′); or combinations thereof.

Contemplated for use with the formulations disclosed herein are agentsthat relieve, prevent, reverse or ameliorate the degeneration of neuronsand/or hair cells of the auris due to free-radicals or the dysfunctionof the mitochondria. Accordingly, some embodiments incorporate the useof one or more agents that modulate the catalytic rate of sirtuincatalyzed deacetylation reactions. In some embodiments, the agent whichmodulates the catalytic rate of sirtuin catalyzed deacetylationreactions is dipyridamole, ZM 336372(3-(dimethylamino)-N-[3-[(4-hydroxybenzoyl)-amino]-4-methylphenyl]benzamide), camptothecin, coumestrol, nordihydroguaiareticacid, esculetin, SRT-1720 (Sirtris), SRT-1460 (Sirtris), SRT-2183(Sirtris), or combinations thereof.

Contemplated for use with the formulations disclosed herein are agentsthat relieve, prevent, reverse or ameliorate the degeneration of neuronsand/or hair cells of the auris due to free-radicals or the dysfunctionof the mitochondria. Accordingly, some embodiments incorporate the useof one or more agents the modulate sirtuin catalyzed deacetylationreactions. In some embodiments, the agent that modulates sirtuincatalyzed deacetylation reactions is a nicotinamide binding antagonist.In some embodiments, the nicotinamide binding antagonist isisonicotinamide or an analog of isonicotinamide. In some embodiments,the analog of isonicotinamide isβ-1′-5-methyl-nicotinamide-2′-deoxyribose;β-D-1′-5-methyl-nico-tinamide-2′-deoxyribofuranoside;β-1′-4,5-dimethyl-nicotinamide-2′-de-oxyribose; orβ-D-1′-4,5-dimethyl-nicotinamide-2′-deoxyribofuranoside. For additionalanalogs of isonicotinamide see U.S. Pat. Nos. 5,985,848; 6,066,722;6,228,847; 6,492,347; 6,803,455; and U.S. Patent Publication Nos.2001/0019823; 2002/0061898; 2002/0132783; 2003/0149261; 2003/0229033;2003/0096830; 2004/0053944; 2004/0110772; and 2004/0181063, which arehereby incorporated by reference for that disclosure.

Glutamate-Receptor Modulators

Contemplated for use with the formulations disclosed herein are agentsthat modulate the production of free-radicals and/or inhibit damage tothe mitochondria. Accordingly, some embodiments incorporate the use ofagents which modulate glutamate receptors. In some embodiments, theglutamate receptor is the AMPA receptor, the NMDA receptor, and/or agroup II or III mGlu receptor.

The over-activation of the AMPA and NMDA glutamate receptors by thebinding of excessive amounts of glutamate, results in the excessiveopening of the ion channels under their control. This results inabnormally high levels of Ca²⁺ and Na⁺ entering the neuron. The influxof Ca²⁺ and Na⁺ into the neuron activates multiple enzymes including,but not limited to, phospholipases, endonucleases, and proteases. Theover-activation of these enzymes results in damage to mitochondria andthe production of ROS.

In some embodiments, the agent that modulates the AMPA receptor is anAMPA receptor antagonist. In some embodiments, the agent whichantagonizes the AMPA receptors is CNQX(6-cyano-7-nitroquinoxaline-2,3-dione); NBQX(2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo[f]quinoxaline-2,3-dione); DNQX(6,7-dinitroquinoxaline-2,3-dione); kynurenic acid;2,3-dihydroxy-6-nitro-7-sulfamoylbenzo-[f]quinoxaline; or combinationsthereof.

In some embodiments, the agent that modulates the NMDA receptor is anNMDA receptor antagonist. In some embodiments, the agent whichantagonizes the NMDA receptor is 1-aminoadamantane, dextromethorphan,dextrorphan, ibogaine, ketamine, nitrous oxide, phencyclidine, riluzole,tiletamine, memantine, dizocilpine, aptiganel, remacimide,7-chlorokynurenate, DCKA (5,7-dichlorokynurenic acid), kynurenic acid,1-aminocyclopropanecarboxylic acid (ACPC), AP7(2-amino-7-phosphonoheptanoic acid), APV(R-2-amino-5-phosphonopentanoate), CPPene(3-[(R)-2-carboxypiperazin-4-yl]-prop-2-enyl-1-phosphonic acid);(+)-(1S,2S)-1-(4-hydroxy-phenyl)-2-(4-hydroxy-4-phenylpiperidino)-1-pro-panol;(1S,2S)-1-(4-hydroxy-3-methoxyphenyl)-2-(4-hydroxy-4-phenylpiperi-dino)-1-propanol;(3R,4S)-3-(4-(4-fluorophenyl)-4-hydroxypiperidin-1-yl-)-chroman-4,7-diol;(1R*,2R*)-1-(4-hydroxy-3-methylphenyl)-2-(4-(4-fluoro-phenyl)-4-hydroxypiperidin-1-yl)-propan-1-ol-mesylate;and/or combinations thereof.

The mGlu receptors, unlike the AMPA and NMDA receptors, do not directlycontrol an ion channel. However, they indirectly control the opening ofion channels by the activation of biochemical cascades. The mGlureceptors are divided into three groups. The members of groups II andIII reduce or inhibit post-synaptic potentials by preventing ordecreasing the formation of cAMP. This causes a reduction in the releaseof neurotransmitters, especially glutamate. GRM7 is the gene whichencodes the mGlu7 receptor, a group III receptor. The agonism of mGlu7results in a decrease in synaptic concentrations of glutamate. Thisameliorates glutamate excitotoxicity.

In some embodiments, the glutamate receptor is a group II mGlu receptor.In some embodiments, the agent which modulates the group II mGlureceptor is a group II mGlu receptor agonist. In some embodiments, thegroup II mGlu receptor agonist is LY389795((−)-2-thia-4-aminobicyclo-hexane-4,6-dicarboxylate); LY379268((−)-2-oxa-4-aminobicyclo-hexane-4,6-dicarboxylate); LY354740((+)-2-aminobicyclo-hexane-2,6dicarboxylate); DCG-IV((2S,2′R,3′R)-2-(2′,3′-dicarboxycyclopropyl)glycine); 2R,4R-APDC(2R,4R-4-aminopyrrolidine-2,4-dicarboxylate), (S)-3C4HPG((S)-3-carboxy-4-hydroxyphenylglycine); (S)-4C3HPG((S)-4-carboxy-3-hydroxyphenylglycine); L-CCG-I((2S,1′S,2′S)-2-(carboxycyclopropyl)glycine); and/or combinationsthereof.

In some embodiments, the mGlu receptor is a group III mGlu receptor. Insome embodiments, the group III mGlu receptor is mGlu7. In someembodiments, the agent that modulates the group III mGlu receptor is agroup III mGlu receptor agonist. In some embodiments, the group III mGlureceptor agonist is ACPT-I((1S,3R,4S)-1-aminocyclopentane-1,3,4-tricarboxylic acid); L-AP4(L-(+)-2-Amino-4-phosphonobutyric acid); (S)-3,4-DCPG((S)-3,4-dicarboxyphenylglycine); (RS)-3,4-DCPG((RS)-3,4-dicarboxyphenylglycine); (RS)-4-phosphonophenylglycine((RS)PPG); AMN082 (,N′-bis(diphenylmethyl)-1,2-ethanediaminedihydrochloride); DCG-IV((2S,2′R,3′R)-2-(2′,3′-dicarboxycyclopropyl)glycine); and/orcombinations thereof. In some embodiments, the mGlu receptor is mGlu7.In some embodiments, the agonist of mGlu7 is AMN082.

RNAi

In some embodiments, where inhibition or down-regulation of a target isdesired (e.g. genes encoding AMPA and NMDA), RNA interference may beutilized. In some embodiments, the agent that inhibits or down-regulatesthe target is an siRNA molecule. In certain instances, the siRNAmolecule inhibits the transcription of a target by RNA interference(RNAi). In some embodiments, a double stranded RNA (dsRNA) molecule withsequences complementary to a target is generated (e.g by PCR). In someembodiments, a 20-25 bp siRNA molecule with sequences complementary to atarget is generated. In some embodiments, the 20-25 bp siRNA moleculehas 2-5 bp overhangs on the 3′ end of each strand, and a 5′ phosphateterminus and a 3′ hydroxyl terminus. In some embodiments, the 20-25 bpsiRNA molecule has blunt ends. For techniques for generating RNAsequences see Molecular Cloning: A Laboratory Manual, second edition(Sambrook et al., 1989) and Molecular Cloning: A Laboratory Manual,third edition (Sambrook and Russel, 2001), jointly referred to herein as“Sambrook”); Current Protocols in Molecular Biology (F. M. Ausubel etal., eds., 1987, including supplements through 2001); Current Protocolsin Nucleic Acid Chemistry John Wiley & Sons, Inc., New York, 2000) whichare hereby incorporated by reference for such disclosure.

In some embodiments, the dsRNA or siRNA molecule is incorporated into acontrolled-release auris-acceptable microsphere or microparticle,hydrogel, paint, foam, in situ forming spongy material, nanocapsule,nanosphere, liposome, actinic-radiation curable gel, solvent releasegel, or thermoreversible gel. In some embodiments, the auris-acceptablemicrosphere, hydrogel, liposome, an auris-acceptable actinic radiationcurable gel, solvent release gel, paint, foam, in situ forming spongymaterial, nanocapsule or nanosphere or thermoreversible gel is injectedinto the inner ear. In some embodiments, the auris-acceptablemicrosphere, hydrogel, liposome, paint, foam, in situ forming spongymaterial, nanocapsule or nanosphere actinic-radiation curable gel,solvent release gel, or thermoreversible gel is injected into thecochlea, the organ of Corti, the vestibular labyrinth, or a combinationthereof.

In certain instances, after administration of the dsRNA or siRNAmolecule, cells at the site of administration (e.g. the cells ofcochlea, organ of Corti, and/or the vestibular labyrinth) aretransformed with the dsRNA or siRNA molecule. In certain instancesfollowing transformation, the dsRNA molecule is cleaved into multiplefragments of about 20-25 bp to yield siRNA molecules. In certaininstances, the fragments have about 2 bp overhangs on the 3′ end of eachstrand.

In certain instances, an siRNA molecule is divided into two strands (theguide strand and the anti-guide strand) by an RNA-induced SilencingComplex (RISC). In certain instances, the guide strand is incorporatedinto the catalytic component of the RISC (i.e. argonaute). In certaininstances, the guide strand binds to a complementary AMPA or NMDA mRNAsequence. In certain instances, the RISC cleaves the AMPA or NMDA mRNA.In certain instances, the expression of the AMPA and NMDA gene isdown-regulated.

In some embodiments, a sequence complementary to a target is ligatedinto a vector. In some embodiments, the sequence is placed between twopromoters. In some embodiments, the promoters are orientated in oppositedirections. In some embodiments, the vector is contacted with a cell. Incertain instances, a cell is transformed with the vector. In certaininstances following transformation, sense and anti-sense strands of thesequence are generated. In certain instances, the sense and anti-sensestrands hybridize to form a dsRNA molecule which is cleaved into siRNAmolecules. In certain instances, the strands hybridize to form an siRNAmolecule. In some embodiments, the vector is a plasmid (e.g pSUPER;pSUPER.neo; pSUPER.neo+gfp).

In some embodiments, the vector is incorporated into acontrolled-release auris-acceptable microsphere or microparticle,hydrogel, paint, forma, in situ forming spongy material, nanocapsule,nanosphere, liposome, an auris-acceptable actinic radiation curable gel,solvent release gel, or thermoreversible gel. In some embodiments, theauris-acceptable microsphere, hydrogel, liposome, an auris-acceptableactinic radiation curable gel, paint, foam, in situ forming spongymaterial, nanocapsule or nanosphere, solvent release gel, orthermoreversible gel is injected into the inner ear. In someembodiments, the auris-acceptable microsphere, hydrogel, liposome, anauris-acceptable actinic radiation curable gel, solvent release gel,paint, foam, in situ forming spongy material, nanocapsule or nanosphereor thermoreversible gel is injected into the cochlea, the organ ofCorti, the vestibular labyrinth, or a combination thereof.

Growth Factors

Some embodiments disclosed herein incorporate the use of agents whichpromote the survival of neurons and otic hair cells. In someembodiments, the agent which promotes the survival of otic hair cells isa growth factor. In some embodiments, the growth factor is a neurotroph.Neurotrophs are growth factors which repair damaged neurons and otichair cells, and/or induce differentiation in progenitor cells. In someembodiments, the neurotroph is brain-derived neurotrophic factor (BDNF),ciliary neurotrophic factor (CNTF), glial cell-line derived neurotrophicfactor (GDNF), neurotrophin-3, neurotrophin-4, and/or combinationsthereof. In some embodiments, the growth factor is an agonist of thefibroblast growth factor (FGF) receptor. In some embodiments, the growthfactor is an agonist of the insulin-like growth factor (IGF).

In some embodiments, the neurotroph is BDNF. BDNF is a neurotroph whichpromotes the survival of existing neurons (e.g. spiral ganglionneurons), and otic hair cells by repairing damaged cells, inhibiting theproduction of ROS, and inhibiting the induction of apoptosis. It alsopromotes the differentiation of neural and otic hair cell progenitors.Further, it protects the cranial VII nerve from degeneration. In someembodiments, BDNF is administered in conjunction with fibroblast growthfactor.

In some embodiments, the neurotroph is neurotrophin-3. Neurotrophin-3promotes the survival of existing neurons and otic hair cells, andpromotes the differentiation of neural and otic hair cell progenitors.Further, it protects the cranial VII nerve from degeneration.

In some embodiments, the neurotroph is CNTF. CNTF promotes the synthesisof neurotransmitters and the growth of neuritis. In some embodiments,CNTF is administered in conjunction with BDNF.

In some embodiments, the neurotroph is GDNF. GDNF expression isincreased by treatment with ototoxic agents. Further, cells treated withexogenous GDNF have higher survival rates after trauma (e.g., oxidativedamage caused by ROS) than untreated cells.

In some embodiments, the FGF receptor agonist is FGF-2. In someembodiments, the IGF receptor agonist is IGF-1. Both the FGF and IGFreceptors are found in the cells comprising the utricle epithelium.

Concentration of Active Agent

In some embodiments, the compositions described herein have aconcentration of active pharmaceutical ingredient between about 0.01% toabout 90%, between about 0.01% to about 50%, between about 0.1% to about70%, between about 0.1% to about 50%, between about 0.1% to about 40%,between about 0.1% to about 30%, between about 0.1% to about 20%,between about 0.1% to about 10%, or between about 0.1% to about 5%, ofthe active ingredient, or pharmaceutically acceptable prodrug or saltthereof, by weight of the composition. In some embodiments, thecompositions described herein have a concentration of activepharmaceutical agent between about 1% to about 50%, between about 5% toabout 50%, between about 10% to about 40%, or between about 10% to about30%, of the active ingredient, or pharmaceutically acceptable prodrug orsalt thereof, by weight of the composition. In some embodiments,formulations described herein comprise about 70% by weight of afree-radical modulator, or pharmaceutically acceptable prodrug or saltthereof, by weight of the formulation. In some embodiments, formulationsdescribed herein comprise about 60% by weight of a free-radicalmodulator, or pharmaceutically acceptable prodrug or salt thereof, byweight of the formulation. In some embodiments, formulations describedherein comprise about 50% by weight of a free-radical modulator, orpharmaceutically acceptable prodrug or salt thereof, by weight of theformulation. In some embodiments, formulations described herein compriseabout 40% by weight of a free-radical modulator, or pharmaceuticallyacceptable prodrug or salt thereof, by weight of the formulation. Insome embodiments, formulations described herein comprise about 30% byweight of a free-radical modulator, or pharmaceutically acceptableprodrug or salt thereof, by weight of the formulation. In someembodiments, formulations described herein comprise about 20% by weightof a free-radical modulator, or pharmaceutically acceptable prodrug orsalt thereof, by weight of the formulation. In some embodiments,formulations described herein comprise about 15% by weight of afree-radical modulating agent, or pharmaceutically acceptable prodrug orsalt thereof, by weight of the formulation. In some embodiments,formulations described herein comprise about 10% by weight of afree-radical modulator by weight of the formulation. In someembodiments, formulations described herein comprise about 5% by weightof a free-radical modulating agent, or pharmaceutically acceptableprodrug or salt thereof, by weight of the formulation. In someembodiments, formulations described herein comprise about 2.5% by weightof a free-radical modulating agent, or pharmaceutically acceptableprodrug or salt thereof, by weight of the formulation. In someembodiments, formulations described herein comprise about 1% by weightof a free-radical modulating agent, or pharmaceutically acceptableprodrug or salt thereof, by weight of the formulation. In someembodiments, formulations described herein comprise about 0.5% by weightof a free-radical modulating agent, or pharmaceutically acceptableprodrug or salt thereof, by weight of the formulation. In someembodiments, formulations described herein comprise about 0.1% by weightof a free-radical modulating agent, or pharmaceutically acceptableprodrug or salt thereof, by weight of the formulation. In someembodiments, formulations described herein comprise about 0.01% byweight of a free-radical modulating agent, or pharmaceuticallyacceptable prodrug or salt thereof, by weight of the formulation. Insome embodiments, the formulations described herein have a concentrationof active pharmaceutical ingredient, or pharmaceutically acceptableprodrug or salt thereof, between about 0.1 to about 70 mg/mL, betweenabout 0.5 mg/mL to about 70 mg/mL, between about 0.5 mg/mL to about 50mg/mL, between about 0.5 mg/mL to about 20 mg/mL, between about 1 mg toabout 70 mg/mL, between about 1 mg to about 50 mg/mL, between about 1mg/mL and about 20 mg/mL, between about 1 mg/mL to about 10 mg/mL, orbetween about 1 mg/mL to about 5 mg/mL, of the active agent, orpharmaceutically acceptable prodrug or salt thereof, by volume of theformulation.

Otic Surgery and Implants

In some embodiments, the pharmaceutical formulations, compositions ordevices described herein are used in combination with (e.g.,implantation, short-term use, long-term use, or removal of) implants(e.g., cochlear implants). As used herein, implants includeauris-interna or auris-media medical devices, examples of which includecochlear implants, hearing sparing devices, hearing-improvement devices,short electrodes, tympanostomy tubes, micro-prostheses or piston-likeprostheses; needles; stem cell transplants; drug delivery devices; anycell-based therapeutic; or the like. In some instances, the implants areused in conjunction with a patient experiencing hearing loss. In someinstances, the hearing loss is present at birth. In some instances, thehearing loss is associated with conditions such as AIED, bacterialmeningitis or the like that lead to cell and/or nerve damage with rapidobliteration of cochlear structures and profound hearing loss.

In some instances, an implant is an immune cell or a stem celltransplant in the ear. In some instances, an implant is a smallelectronic device that has an external portion placed behind the ear,and a second portion that is surgically placed under the skin that helpsprovide a sense of sound to a person who is profoundly deaf or severelyhard-of-hearing. By way of example, such cochlear medical deviceimplants bypass damaged portions of the ear and directly stimulate theauditory nerve. In some instances cochlear implants are used in singlesided deafness. In some instances cochlear implants are used fordeafness in both ears.

In some embodiments, administration of a free-radical modulating agentcomposition or device described herein in combination with an oticintervention (e.g., an intratympanic injection, a stapedectomy, atympanostomy, a medical device implant or a cell-based transplant)delays or prevents collateral damage to auris structures, e.g.,irritation, oxidative damage, caused by the external otic intervention(e.g., installation of an external device and/or cells in the ear). Insome embodiments, administration of a free-radical modulating agentcomposition or device described herein in combination with an implantallows for a more effective restoration of hearing loss compared to animplant alone.

In some embodiments, administration of a free-radical modulating agentcomposition or device described herein reduces damage to cochlearstructures caused by underlying conditions (e.g., bacterial meningitis,autoimmune ear disease (AIED)) allowing for successful cochlear deviceimplantation. In some embodiments, administration of a composition ordevice described herein, in conjunction with otic surgery, medicaldevice implantation and/or cell transplantation, reduces or preventscell damage and/or inflammation associated with otic surgery, medicaldevice implantation and/or cell transplantation.

In some embodiments, administration of a free-radical modulating agentcomposition or device described herein (e.g., a composition or devicecomprising an antioxidant) in conjunction with a cochlear implant orstem cell transplant has a trophic effect (e.g., promotes healthy growthof cells and/or healing of tissue in the area of an implant ortransplant). In some embodiments, a trophic effect is desirable duringotic surgery or during intratympanic injection procedures. In someembodiments, a trophic effect is desirable after installation of amedical device or after a cell transplant. In some of such embodiments,the free-radical modulating agent compositions or devices describedherein are administered via direct cochlear injection, through achochleostomy or via deposition on the round window.

In some embodiments, administration of a free-radical modulating agentcomposition reduces oxidative damage and/or cell death associated withotic surgery, implantation of a medical device or a cell transplant. Insome instances, perfusion of a surgical area with a free-radicalmodulating agent formulation described herein reduces or eliminatespost-surgical and/or post-implantation complications (e.g., cell damage,osteoneogenesis or the like). In some instances, perfusion of a surgicalarea with a formulation described herein reduces post-surgery orpost-implantation recuperation time.

In one aspect, the formulations described herein, and modes ofadministration thereof, are applicable to methods of direct perfusion ofthe inner ear compartments. Thus, the formulations described herein areuseful in combination with otic interventions. In some embodiments, anotic intervention is an implantation procedure (e.g., implantation of ahearing device in the cochlea). In some embodiments, an oticintervention is a surgical procedure including, by way of non-limitingexamples, cochleostomy, labyrinthotomy, mastoidectomy, stapedectomy,stapedotomy, tympanostomy, endolymphatic sacculotomy or the like. Insome embodiments, the inner ear compartments are perfused with aformulation described herein prior to otic intervention, during oticintervention, or after otic intervention, or a combination thereof.

In some embodiments, when perfusion is carried out in combination withotic intervention, the free-radical modulating agent compositions areimmediate release compositions (e.g., a composition comprisingresveratrol). In some of such embodiments, the immediate releaseformulations described herein are non-thickened compositions and aresubstantially free of extended release components (e.g., gellingcomponents such as polyoxyethylene-polyoxypropylene copolymers). In someof such embodiments, the compositions contain less than 5% of theextended release components (e.g., gelling components such aspolyoxyethylene-polyoxypropylene triblock copolymers) by weight of theformulation. In some of such embodiments, the compositions contain lessthan 2% of the extended release components (e.g., gelling componentssuch as polyoxyethylene-polyoxypropylene triblock copolymers) by weightof the formulation. In some of such embodiments, the compositionscontain less than 1% of the extended release components (e.g., gellingcomponents such as polyoxyethylene-polyoxypropylene triblock copolymers)by weight of the formulation. In some of such embodiments, a compositiondescribed herein that is used for perfusion of a surgical area containssubstantially no gelling component and is an immediate releasecomposition.

In certain embodiments, a composition described herein is administeredbefore an otic intervention (e.g., before implantation of a medicaldevice or a cell-based therapeutic). In certain embodiments, acomposition described herein is administered during an otic intervention(e.g., during implantation of a medical device or a cell-basedtherapeutic). In other embodiments, a composition described herein isadministered after an otic intervention (e.g., after implantation of amedical device or a cell-based therapeutic). In some of suchembodiments, a composition described herein that is administered afterthe otic intervention is an intermediate release or extended releasecomposition and contains gelling components as described herein. In someembodiments, an implant (e.g., a tympanostomy tube) is coated with acomposition or device described herein prior to insertion in the ear.

Presented below (Table 1) are examples of active agents contemplated foruse with the formulations and devices disclosed herein. One or moreactive agents are used in any of the formulations or devices describedherein. Active Agents (including pharmaceutically acceptable salts,prodrugs of these active agents) for use with the Formulations DisclosedHerein:

TABLE 1 Auris Condition Therapeutic Agent Benign ParoxysmalDiphenhydramine Positional Vertigo Benign Paroxysmal LorazepamPositional Vertigo Benign Paroxysmal Meclizine Positional Vertigo BenignParoxysmal Oldansetron Positional Vertigo Hearing Loss Estrogen HearingLoss Resveratrol Hearing Loss Deferoxamine Hearing Loss Estrogen andprogesterone (E + P) Hearing Loss Folic acid Hearing Loss LactatedRinger's with 0.03% Ofloxacin Hearing Loss Methotrexate Hearing LossN-acetyl cysteine Middle Ear Effusion Pneumonococcal vaccine OtitisExterna Diclofenac sodium; dexotc Otitis Externa, AcuteAL-15469A/AL-38905 Otitis Media Amoxicillin/clavulanate Otitis MediaDornase alfa Otitis Media Echinacea purpurea Otitis Media Faropenemmedoxomil Otitis Media Levofloxacin Otitis Media PNCRM9 Otitis MediaPneumococcal vaccine Otitis Media Telithromycin Otitis Media Zmax OtitisMedia with Lansoprazole Effusion Otitis Media, Acute AL-15469A; AL-38905Otitis Media, Acute Amoxicillin Otitis Media, AcuteAmoxicillin-clavulanate Otitis Media, Acute Azithromycin Otitis Media,Acute Azithromycin SR Otitis Media, Acute Cefdinir Otitis Media, AcuteHyland's earache drops Otitis Media, Acute Montelukast Otitis Media,Acute Pneumonococcal vaccine Otitis Media, Acute AL-15469A/AL38905 withTypanostomy Tubes Otitis Media, Chronic Sulfamethoxazole- trimethoprimOtitis Media, Azithromycin Suppurative Otitis Media, TelithromycinSuppurative Otosclerosis Acetylcysteine Ototoxicity Aspirin TinnitusAcamprosate Tinnitus Gabapentin Tinnitus Modafinil Tinnitus NeramexaneTinnitus Neramexane mesylate Tinnitus Piribedil Tinnitus VardenafilTinnitus Vestipitant + Paroxetine Tinnitus Vestiplitant Tinnitus Zincsulfate

General Methods of Sterilization

Provided herein are otic compositions that ameliorate or lessen oticdisorders described herein. Further provided herein are methodscomprising the administration of said otic compositions. In someembodiments, the compositions or devices are sterilized. Included withinthe embodiments disclosed herein are means and processes forsterilization of a pharmaceutical composition or device disclosed hereinfor use in humans. The goal is to provide a safe pharmaceutical product,relatively free of infection causing micro-organisms. The U.S. Food andDrug Administration has provided regulatory guidance in the publication“Guidance for Industry: Sterile Drug Products Produced by AsepticProcessing” available at: http://www.fda.gov/cder/guidance/5882fnl.htm,which is incorporated herein by reference in its entirety.

As used herein, sterilization means a process used to destroy or removemicroorganisms that are present in a product or packaging. Any suitablemethod available for sterilization of objects and compositions is used.Available methods for the inactivation of microorganisms include, butare not limited to, the application of extreme heat, lethal chemicals,or gamma radiation. In some embodiments is a process for the preparationof an otic therapeutic formulation comprising subjecting the formulationto a sterilization method selected from heat sterilization, chemicalsterilization, radiation sterilization or filtration sterilization. Themethod used depends largely upon the nature of the device or compositionto be sterilized. Detailed descriptions of many methods of sterilizationare given in Chapter 40 of Remington: The Science and Practice ofPharmacy published by Lippincott, Williams & Wilkins, and isincorporated by reference with respect to this subject matter.

Sterilization by Heat

Many methods are available for sterilization by the application ofextreme heat. One method is through the use of a saturated steamautoclave. In this method, saturated steam at a temperature of at least121° C. is allowed to contact the object to be sterilized. The transferof heat is either directly to the microorganism, in the case of anobject to be sterilized, or indirectly to the microorganism by heatingthe bulk of an aqueous solution to be sterilized. This method is widelypracticed as it allows flexibility, safety and economy in thesterilization process.

Dry heat sterilization is a method which is used to kill microorganismsand perform depyrogenation at elevated temperatures. This process takesplace in an apparatus suitable for heating HEPA-filteredmicroorganism-free air to temperatures of at least 130-180° C. for thesterilization process and to temperatures of at least 230-250° C. forthe depyrogenation process. Water to reconstitute concentrated orpowdered formulations is also sterilized by autoclave. In someembodiments, the formulations described herein comprise micronizedfree-radical modulating agents (e.g., micronized SRT-501 powder) thatare sterilized by dry heating, e.g., heating for about 7-11 hours atinternal powder temperatures of 130-140° C., or for 1-2 hours atinternal temperatures of 150-180° C.

Chemical Sterilization

Chemical sterilization methods are an alternative for products that donot withstand the extremes of heat sterilization. In this method, avariety of gases and vapors with germicidal properties, such as ethyleneoxide, chlorine dioxide, formaldehyde or ozone are used as theanti-apoptotic agents. The germicidal activity of ethylene oxide, forexample, arises from its ability to serve as a reactive alkylatingagent. Thus, the sterilization process requires the ethylene oxidevapors to make direct contact with the product to be sterilized.

Radiation Sterilization

One advantage of radiation sterilization is the ability to sterilizemany types of products without heat degradation or other damage. Theradiation commonly employed is beta radiation or alternatively, gammaradiation from a ⁶⁰Co source. The penetrating ability of gamma radiationallows its use in the sterilization of many product types, includingsolutions, compositions and heterogeneous mixtures. The germicidaleffects of irradiation arise from the interaction of gamma radiationwith biological macromolecules. This interaction generates chargedspecies and free-radicals. Subsequent chemical reactions, such asrearrangements and cross-linking processes, result in the loss of normalfunction for these biological macromolecules. The formulations describedherein are also optionally sterilized using beta irradiation.

Filtration

Filtration sterilization is a method used to remove but not destroymicroorganisms from solutions. Membrane filters are used to filterheat-sensitive solutions. Such filters are thin, strong, homogenouspolymers of mixed cellulosic esters (MCE), polyvinylidene fluoride (PVF;also known as PVDF), or polytetrafluoroethylene (PTFE) and have poresizes ranging from 0.1 to 0.22 μm. Solutions of various characteristicsare optionally filtered using different filter membranes. For example,PVF and PTFE membranes are well suited to filtering organic solventswhile aqueous solutions are filtered through PVF or MCE membranes.Filter apparatus are available for use on many scales ranging from thesingle point-of-use disposable filter attached to a syringe up tocommercial scale filters for use in manufacturing plants. The membranefilters are sterilized by autoclave or chemical sterilization.Validation of membrane filtration systems is performed followingstandardized protocols (Microbiological Evaluation of Filters forSterilizing Liquids, Vol 4, No. 3. Washington, D.C: Health IndustryManufacturers Association, 1981) and involve challenging the membranefilter with a known quantity (ca. 10^(7/) cm²) of unusually smallmicroorganisms, such as Brevundimonas diminuta (ATCC 19146).

Pharmaceutical compositions are optionally sterilized by passing throughmembrane filters. Formulations comprising nanoparticles (U.S. Pat. No.6,139,870) or multilamellar vesicles (Richard et al., InternationalJournal of Pharmaceutics (2006), 312(1-2): 144-50) are amenable tosterilization by filtration through 0.22 μm filters without destroyingtheir organized structure.

In some embodiments, the methods disclosed herein comprise sterilizingthe formulation (or components thereof) by means of filtrationsterilization. In another embodiment the auris-acceptable otictherapeutic agent formulation comprises a particle wherein the particleformulation is suitable for filtration sterilization. In a furtherembodiment said particle formulation comprises particles of less than300 nm in size, of less than 200 nm in size, of less than 100 nm insize. In another embodiment the auris-acceptable formulation comprises aparticle formulation wherein the sterility of the particle is ensured bysterile filtration of the precursor component solutions. In anotherembodiment the auris-acceptable formulation comprises a particleformulation wherein the sterility of the particle formulation is ensuredby low temperature sterile filtration. In a further embodiment, lowtemperature sterile filtration is carried out at a temperature between 0and 30° C., between 0 and 20° C., between 0 and 10° C., between 10 and20° C., or between 20 and 30° C.

In another embodiment is a process for the preparation of anauris-acceptable particle formulation comprising: filtering the aqueoussolution containing the particle formulation at low temperature througha sterilization filter; lyophilizing the sterile solution; andreconstituting the particle formulation with sterile water prior toadministration. In some embodiments, a formulation described herein ismanufactured as a suspension in a single vial formulation containing themicronized active pharmaceutical ingredient. A single vial formulationis prepared by aseptically mixing a sterile poloxamer solution withsterile micronized active ingredient (e.g., resveratrol) andtransferring the formulation to sterile pharmaceutical containers. Insome embodiments, a single vial containing a formulation describedherein as a suspension is resuspended before dispensing and/oradministration.

In specific embodiments, filtration and/or filling procedures arecarried out at about 5° C. below the gel temperature (Tgel) of aformulation described herein and with viscosity below a theoreticalvalue of 100 cP to allow for filtration in a reasonable time using aperistaltic pump.

In another embodiment the auris-acceptable otic therapeutic agentformulation comprises a nanoparticle formulation wherein thenanoparticle formulation is suitable for filtration sterilization. In afurther embodiment the nanoparticle formulation comprises nanoparticlesof less than 300 nm in size, of less than 200 nm in size, or of lessthan 100 nm in size. In another embodiment the auris-acceptableformulation comprises a microsphere formulation wherein the sterility ofthe microsphere is ensured by sterile filtration of the precursororganic solution and aqueous solutions. In another embodiment theauris-acceptable formulation comprises a thermoreversible gelformulation wherein the sterility of the gel formulation is ensured bylow temperature sterile filtration. In a further embodiment, the lowtemperature sterile filtration occurs at a temperature between 0 and 30°C., or between 0 and 20° C., or between 0 and 10° C., or between 10 and20° C., or between 20 and 30° C. In another embodiment is a process forthe preparation of an auris-acceptable thermoreversible gel formulationcomprising: filtering the aqueous solution containing thethermoreversible gel components at low temperature through asterilization filter; lyophilizing the sterile solution; andreconstituting the thermoreversible gel formulation with sterile waterprior to administration.

In certain embodiments, the active ingredients are dissolved in asuitable vehicle (e.g. a buffer) and sterilized separately (e.g., byheat treatment, filtration, gamma radiation). In some instances, theactive ingredients are sterilized separately in a dry state. In someinstances, the active ingredients are sterilized as a suspension or as acolloidal suspension. The remaining excipients (e.g., fluid gelcomponents present in auris formulations) are sterilized in a separatestep by a suitable method (e.g., filtration and/or irradiation of acooled mixture of excipients); the two solutions that are separatelysterilized are then mixed aseptically to provide a final aurisformulation. In some instances, the final aseptic mixing is performedjust prior to administration of a formulation described herein.

In some instances, conventionally used methods of sterilization (e.g.,heat treatment (e.g., in an autoclave), gamma irradiation, filtration)lead to irreversible degradation of polymeric components (e.g.,thermosetting, gelling or mucoadhesive polymer components) and/or theactive agent in the formulation. In some instances, sterilization of anauris formulation by filtration through membranes (e.g., 0.2 μMmembranes) is not possible if the formulation comprises thixotropicpolymers that gel during the process of filtration.

Accordingly, provided herein are methods for sterilization of aurisformulations that prevent degradation of polymeric components (e.g.,thermosetting and/or gelling and/or mucoadhesive polymer components)and/or the active agent during the process of sterilization. In someembodiments, degradation of the active agent (e.g., any therapeutic oticagent described herein) is reduced or eliminated through the use ofspecific pH ranges for buffer components and specific proportions ofgelling agents in the formulations. In some embodiments, the choice ofan appropriate gelling agent and/or thermosetting polymer allows forsterilization of formulations described herein by filtration. In someembodiments, the use of an appropriate thermosetting polymer and anappropriate copolymer (e.g., a gelling agent) in combination with aspecific pH range for the formulation allows for high temperaturesterilization of formulations described with substantially nodegradation of the therapeutic agent or the polymeric excipients. Anadvantage of the methods of sterilization provided herein is that, incertain instances, the formulations are subjected to terminalsterilization via autoclaving without any loss of the active agentand/or excipients and/or polymeric components during the sterilizationstep and are rendered substantially free of microbes and/or pyrogens.

Microorganisms

Provided herein are auris-acceptable compositions or devices thatameliorate or lessen otic disorders described herein. Further providedherein are methods comprising the administration of said oticcompositions. In some embodiments, the compositions or devices aresubstantially free of microorganisms. Acceptable bioburden or sterilitylevels are based on applicable standards that define therapeuticallyacceptable compositions, including but not limited to United StatesPharmacopeia Chapters <1111> et seq. For example, acceptable sterility(e.g., bioburden) levels include about 10 colony forming units (cfu) pergram of formulation, about 50 cfu per gram of formulation, about 100 cfuper gram of formulation, about 500 cfu per gram of formulation or about1000 cfu per gram of formulation. In some embodiments, acceptablebioburden levels or sterility for formulations include less than 10cfu/mL, less that 50 cfu/mL, less than 500 cfu/mL or less than 1000cfu/mL microbial agents. In addition, acceptable bioburden levels orsterility include the exclusion of specified objectionablemicrobiological agents. By way of example, specified objectionablemicrobiological agents include but are not limited to Escherichia coli(E. coli), Salmonella sp., Pseudomonas aeruginosa (P. aeruginosa) and/orother specific microbial agents.

Sterility of the auris-acceptable otic therapeutic agent formulation isconfirmed through a sterility assurance program in accordance withUnited States Pharmacopeia Chapters <61>, <62> and <71>. A key componentof the sterility assurance quality control, quality assurance andvalidation process is the method of sterility testing. Sterilitytesting, by way of example only, is performed by two methods. The firstis direct inoculation wherein a sample of the composition to be testedis added to growth medium and incubated for a period of time up to 21days. Turbidity of the growth medium indicates contamination. Drawbacksto this method include the small sampling size of bulk materials whichreduces sensitivity, and detection of microorganism growth based on avisual observation. An alternative method is membrane filtrationsterility testing. In this method, a volume of product is passed througha small membrane filter paper. The filter paper is then placed intomedia to promote the growth of microorganisms. This method has theadvantage of greater sensitivity as the entire bulk product is sampled.The commercially available Millipore Steritest sterility testing systemis optionally used for determinations by membrane filtration sterilitytesting. For the filtration testing of creams or ointments Steritestfilter system No. TLHVSL210 are used. For the filtration testing ofemulsions or viscous products Steritest filter system No. TLAREM210 orTDAREM210 are used. For the filtration testing of pre-filled syringesSteritest filter system No. TTHASY210 are used. For the filtrationtesting of material dispensed as an aerosol or foam Steritest filtersystem No. TTHVA210 are used. For the filtration testing of solublepowders in ampoules or vials Steritest filter system No. TTHADA210 orTTHADV210 are used.

Testing for E. coli and Salmonella includes the use of lactose brothsincubated at 30-35° C. for 24-72 hours, incubation in MacConkey and/orEMB agars for 18-24 hours, and/or the use of Rappaport medium. Testingfor the detection of P. aeruginosa includes the use of NAC agar. UnitedStates Pharmacopeia Chapter <62> further enumerates testing proceduresfor specified objectionable microorganisms.

In certain embodiments, any controlled release formulation describedherein has less than about 60 colony forming units (CFU), less thanabout 50 colony forming units, less than about 40 colony forming units,or less than about 30 colony forming units of microbial agents per gramof formulation. In certain embodiments, the otic formulations describedherein are formulated to be isotonic with the endolymph and/or theperilymph.

Endotoxins

Provided herein are otic compositions that ameliorate or lessen oticdisorders described herein. Further provided herein are methodscomprising the administration of said otic compositions. In someembodiments, the compositions or devices are substantially free ofendotoxins. An additional aspect of the sterilization process is theremoval of by-products from the killing of microorganisms (hereinafter,“Product”). The process of depyrogenation removes pyrogens from thesample. Pyrogens are endotoxins or exotoxins which induce an immuneresponse. An example of an endotoxin is the lipopolysaccharide (LPS)molecule found in the cell wall of gram-negative bacteria. Whilesterilization procedures such as autoclaving or treatment with ethyleneoxide kill the bacteria, the LPS residue induces a proinflammatoryimmune response, such as septic shock. Because the molecular size ofendotoxins can vary widely, the presence of endotoxins is expressed in“endotoxin units” (EU). One EU is equivalent to 100 picograms of E. coliLPS. Humans can develop a response to as little as 5 EU/kg of bodyweight. The bioburden (e.g., microbial limit) and/or sterility (e.g.,endotoxin level) is expressed in any units as recognized in the art. Incertain embodiments, otic compositions described herein contain lowerendotoxin levels (e.g. <4 EU/kg of body weight of a subject) whencompared to conventionally acceptable endotoxin levels (e.g., 5 EU/kg ofbody weight of a subject). In some embodiments, the auris-acceptableotic therapeutic agent formulation has less than about 5 EU/kg of bodyweight of a subject. In other embodiments, the auris-acceptable otictherapeutic agent formulation has less than about 4 EU/kg of body weightof a subject. In additional embodiments, the auris-acceptable otictherapeutic agent formulation has less than about 3 EU/kg of body weightof a subject. In additional embodiments, the auris-acceptable otictherapeutic agent formulation has less than about 2 EU/kg of body weightof a subject.

In some embodiments, the auris-acceptable otic therapeutic agentformulation or device has less than about 5 EU/kg of formulation. Inother embodiments, the auris-acceptable otic therapeutic agentformulation has less than about 4 EU/kg of formulation. In additionalembodiments, the auris-acceptable otic therapeutic agent formulation hasless than about 3 EU/kg of formulation. In some embodiments, theauris-acceptable otic therapeutic agent formulation has less than about5 EU/kg Product. In other embodiments, the auris-acceptable otictherapeutic agent formulation has less than about 1 EU/kg Product. Inadditional embodiments, the auris-acceptable otic therapeutic agentformulation has less than about 0.2 EU/kg Product. In some embodiments,the auris-acceptable otic therapeutic agent formulation has less thanabout 5 EU/g of unit or Product. In other embodiments, theauris-acceptable otic therapeutic agent formulation has less than about4 EU/g of unit or Product. In additional embodiments, theauris-acceptable otic therapeutic agent formulation has less than about3 EU/g of unit or Product. In some embodiments, the auris-acceptableotic therapeutic agent formulation has less than about 5 EU/mg of unitor Product. In other embodiments, the auris-acceptable otic therapeuticagent formulation has less than about 4 EU/mg of unit or Product. Inadditional embodiments, the auris-acceptable otic therapeutic agentformulation has less than about 3 EU/mg of unit or Product. In certainembodiments, otic compositions described herein contain from about 1 toabout 5 EU/mL of formulation. In certain embodiments, otic compositionsdescribed herein contain from about 2 to about 5 EU/mL of formulation,from about 3 to about 5 EU/mL of formulation, or from about 4 to about 5EU/mL of formulation.

In certain embodiments, otic compositions or devices described hereincontain lower endotoxin levels (e.g. <0.5 EU/mL of formulation) whencompared to conventionally acceptable endotoxin levels (e.g., 0.5 EU/mLof formulation). In some embodiments, the auris-acceptable otictherapeutic agent formulation or device has less than about 0.5 EU/mL offormulation. In other embodiments, the auris-acceptable otic therapeuticagent formulation has less than about 0.4 EU/mL of formulation. Inadditional embodiments, the auris-acceptable otic therapeutic agentformulation has less than about 0.2 EU/mL of formulation.

Pyrogen detection, by way of example only, is performed by severalmethods. Suitable tests for sterility include tests described in UnitedStates Pharmacopoeia (USP)<71> Sterility Tests (23rd edition, 1995). Therabbit pyrogen test and the Limulus amebocyte lysate test are bothspecified in the United States Pharmacopeia Chapters <85> and <151>(USP23/NF 18, Biological Tests, The United States PharmacopeialConvention, Rockville, Md., 1995). Alternative pyrogen assays have beendeveloped based upon the monocyte activation-cytokine assay. Uniformcell lines suitable for quality control applications have been developedand have demonstrated the ability to detect pyrogenicity in samples thathave passed the rabbit pyrogen test and the Limulus amebocyte lysatetest (Taktak et al, J. Pharm. Pharmacol. (1990), 43:578-82). In anadditional embodiment, the auris-acceptable otic therapeutic agentformulation is subject to depyrogenation. In a further embodiment, theprocess for the manufacture of the auris-acceptable otic therapeuticagent formulation comprises testing the formulation for pyrogenicity. Incertain embodiments, the formulations described herein are substantiallyfree of pyrogens.

pH and Practical Osmolarity

In some embodiments, an otic composition or device disclosed herein isformulated to provide an ionic balance that is compatible with inner earfluids (e.g., endolymph and/or perilymph).

In certain instances, the ionic composition of the endolymph andperilymph regulate the electrochemical impulses of hair cells and thushearing. In certain instances, changes in the conduction ofelectrochemical impulses along otic hair cells results in hearing loss.In certain instances, changes in the ionic balance of the endolymph orperilymph results in complete hearing loss. In certain instances,changes in the ionic balance of the endolymph or perilymph results inpartial hearing loss. In certain instances, changes in the ionic balanceof the endolymph or perilymph results in permanent hearing loss. Incertain instances, changes in the ionic balance of the endolymph orperilymph results in temporary hearing loss.

In some embodiments, a composition or device disclosed herein isformulated in order to not disrupt the ionic balance of the endolymph.In some embodiments, a composition or device disclosed herein has anionic balance that is the same as or substantially the same as theendolymph. In some embodiments, a composition or device disclosed hereindoes not does not disrupt the ionic balance of the endolymph so as toresult in parital or complete hearing loss. In some embodiments, acomposition or device disclosed herein does not does not disrupt theionic balance of the endolymph so as to result in temporary or permanenthearing loss.

In some embodiments, a composition or device disclosed herein does notsubstantially disrupt the ionic balance of the perilymph. In someembodiments, a composition or device disclosed herein has an ionicbalance that is the same as or substantially the same as the perilymph.In some embodiments, a composition or device disclosed herein does notresult in parital or complete hearing loss as the composition or devicedoes not disrupt the ionic balance of the perilymph. In someembodiments, a composition or device disclosed herein does not result intemporary or permanent hearing loss as the composition or device doesnot disrupt the ionic balance of the perilymph.

As used herein, “practical osmolarity/osmolality” or “deliverableosmolarity/osmolality” means the osmolarity/osmolality of a compositionor device as determined by measuring the osmolarity/osmolality of theactive agent and all excipients except the gelling and/or the thickeningagent (e.g., polyoxyethylene-polyooxypropylene copolymers,carboxymethylcellulose or the like). The practical osmolarity of acomposition or device disclosed herein is measured by a suitable method,e.g., a freezing point depression method as described in Viegas et. al.,Int. J. Pharm., 1998, 160, 157-162. In some instances, the practicalosmolarity of a composition or device disclosed herein is measured byvapor pressure osmometry (e.g., vapor pressure depression method) thatallows for determination of the osmolarity of a composition or device athigher temperatures. In some instances, vapor pressure depression methodallows for determination of the osmolarity of a composition or devicecomprising a gelling agent (e.g., a thermoreversible polymer) at ahigher temperature wherein the gelling agent is in the form of a gel.

In some embodiments, the osmolarity at a target site of action (e.g.,the perilymph) is about the same as the delivered osmolarity (i.e.,osmolarity of materials that cross or penetrate the round windowmembrane) of a composition or device described herein. In someembodiments, a composition or device described herein has a deliverableosmolarity of about 150 mOsm/L to about 500 mOsm/L, about 250 mOsm/L toabout 500 mOsm/L, about 250 mOsm/L to about 350 mOsm/L, about 280 mOsm/Lto about 370 mOsm/L or about 250 mOsm/L to about 320 mOsm/L.

The practical osmolality of an otic composition or device disclosedherein is from about 100 mOsm/kg to about 1000 mOsm/kg, from about 200mOsm/kg to about 800 mOsm/kg, from about 250 mOsm/kg to about 500mOsm/kg, or from about 250 mOsm/kg to about 320 mOsm/kg, or from about250 mOsm/kg to about 350 mOsm/kg or from about 280 mOsm/kg to about 320mOsm/kg. In some embodiments, a composition or device described hereinhas a practical osmolarity of about 100 mOsm/L to about 1000 mOsm/L,about 200 mOsm/L to about 800 mOsm/L, about 250 mOsm/L to about 500mOsm/L, about 250 mOsm/L to about 350 mOsm/L, about 250 mOsm/L to about320 mOsm/L, or about 280 mOsm/L to about 320 mOsm/L.

The main cation present in the endolymph is potassium. In addition theendolymph has a high concentration of positively charged amino acids.The main cation present in the perilymph is sodium. In certaininstances, the ionic composition of the endolymph and perilymph regulatethe electrochemical impulses of hair cells. In certain instances, anychange in the ionic balance of the endolymph or perilymph results in aloss of hearing due to changes in the conduction of electrochemicalimpulses along otic hair cells. In some embodiments, a compositiondisclosed herein does not disrupt the ionic balance of the perilymph. Insome embodiments, a composition disclosed herein has an ionic balancethat is the same as or substantially the same as the perilymph. In someembodiments, a composition disclosed herein does not disrupt the ionicbalance of the endolymph. In some embodiments, a composition disclosedherein has an ionic balance that is the same as or substantially thesame as the endolymph. In some embodiments, an otic formulationdescribed herein is formulated to provide an ionic balance that iscompatible with inner ear fluids (e.g., endolymph and/or perilymph).

The endolymph and the perilymph have a pH that is close to thephysiological pH of blood. The endolymph has a pH range of about7.2-7.9; the perilymph has a pH range of about 7.2-7.4. The in situ pHof the proximal endolymph is about 7.4 while the pH of distal endolymphis about 7.9.

In some embodiments, the pH of a composition described herein isadjusted (e.g., by use of a buffer) to an endolymph-compatible pH rangeof about 5.5 to 9.0. In specific embodiments, the pH of a compositiondescribed herein is adjusted to a perilymph-suitable pH range of about5.5 to about 9.0. In some embodiments, the pH of a composition describedherein is adjusted to a perilymph-suitable range of about 5.5 to about8.0, about 6 to about 8.0 or about 6.6 to about 8.0. In someembodiments, the pH of a composition described herein is adjusted to aperilymph-suitable pH range of about 7.0-7.6.

In some embodiments, useful formulations also include one or more pHadjusting agents or buffering agents. Suitable pH adjusting agents orbuffers include, but are not limited to acetate, bicarbonate, ammoniumchloride, citrate, phosphate, pharmaceutically acceptable salts thereofand combinations or mixtures thereof.

In one embodiment, when one or more buffers are utilized in theformulations of the present disclosure, they are combined, e.g., with apharmaceutically acceptable vehicle and are present in the finalformulation, e.g., in an amount ranging from about 0.1% to about 20%,from about 0.5% to about 10%. In certain embodiments of the presentdisclosure, the amount of buffer included in the gel formulations are anamount such that the pH of the gel formulation does not interfere withthe body's natural buffering system.

In one embodiment, diluents are also used to stabilize compounds becausethey can provide a more stable environment. Salts dissolved in bufferedsolutions (which also can provide pH control or maintenance) areutilized as diluents in the art, including, but not limited to aphosphate buffered saline solution.

In some embodiments, any gel formulation described herein has a pH thatallows for sterilization (e.g, by filtration or aseptic mixing or heattreatment and/or autoclaving (e.g., terminal sterilization) of a gelformulation without degradation of the pharmaceutical agent (e.g.,free-radical modulating agent) or the polymers comprising the gel. Inorder to reduce hydrolysis and/or degradation of the otic agent and/orthe gel polymer during sterilization, the buffer pH is designed tomaintain pH of the formulation in the 7-8 range during the process ofsterilization (e.g., high temperature autoclaving).

In specific embodiments, any gel formulation described herein has a pHthat allows for terminal sterilization (e.g, by heat treatment and/orautoclaving) of a gel formulation without degradation of thepharmaceutical agent (e.g., free-radical modulating agent) or thepolymers comprising the gel. For example, in order to reduce hydrolysisand/or degradation of the otic agent and/or the gel polymer duringautoclaving, the buffer pH is designed to maintain pH of the formulationin the 7-8 range at elevated temperatures. Any appropriate buffer isused depending on the otic agent used in the formulation. In someinstances, since pK_(a) of TRIS decreases as temperature increases atapproximately −0.03/° C. and pK_(a) of PBS increases as temperatureincreases at approximately 0.003/° C., autoclaving at 250° F. (121° C.)results in a significant downward pH shift (i.e. more acidic) in theTRIS buffer whereas a relatively much less upward pH shift in the PBSbuffer and therefore much increased hydrolysis and/or degradation of anotic agent in TRIS than in PBS. Degradation of an otic agent is reducedby the use of an appropriate combination of a buffer and polymericadditives (e.g. CMC) as described herein.

In some embodiments, a formulation pH of between about 5.0 and about9.0, between about 5.5 and about 8.5, between about 6.0 and about 7.6,between about 7 and about 7.8, between about 7.0 and about 7.6, betweenabout 7.2 and 7.6, or between about 7.2 and about 7.4 is suitable forsterilization (e.g., by filtration or aseptic mixing or heat treatmentand/or autoclaving (e.g., terminal sterilization)) of auris formulationsdescribed herein. In specific embodiments a formulation pH of about 6.0,about 6.5, about 7.0, about 7.1, about 7.2, about 7.3, about 7.4, about7.5, or about 7.6 is suitable for sterilization (e.g., by filtration oraseptic mixing or heat treatment and/or autoclaving (e.g., terminalsterilization)) of any composition descibed herein.

In some embodiments, the formulations have a pH as described herein, andinclude a thickening agent (e.g., a vicosity enhancing agent) such as,by way of non-limiting example, a cellulose based thickening agentdescribed herein. In some instances, the addition of a secondary polymer(e.g., a thickening agent) and a pH of formulation as described herein,allows for sterilization of a formulation described herein without anysubstantial degradation of the otic agent and/or the polymer componentsin the otic formulation. In some embodiments, the ratio of athermoreversible poloxamer to a thickening agent in a formulation thathas a pH as described herein, is about 40:1, about 35:1, about 30:1,about 25:1, about 20:1, about 15:1 about 10:1, or about 5:1. Forexample, in certain embodiments, a sustained and/or extended releaseformulation described herein comprises a combination of poloxamer 407(pluronic F127) and carboxymethylcellulose (CMC) in a ratio of about40:1, about 35:1, about 30:1, about 25:1, about 20:1, about 15:1, about10:1 or about 5:1.

In some embodiments, the amount of thermoreversible polymer in anyformulation described herein is about 10%, about 15%, about 20%, about25%, about 30%, about 35% or about 40% of the total weight of theformulation. In some embodiments, the amount of thermoreversible polymerin any formulation described herein is about 10%, about 11%, about 12%,about 13%, about 14%, about 15%, about 16%, about 17%, about 18%, about19%, about 20%, about 21%, about 22%, about 23%, about 24% or about 25%of the total weight of the formulation. In some embodiments, the amountof thermoreversible polymer (e.g., pluronic F127) in any formulationdescribed herein is about 7.5% of the total weight of the formulation.In some embodiments, the amount of thermoreversible polymer (e.g.,pluronic F 127) in any formulation described herein is about 10% of thetotal weight of the formulation. In some embodiments, the amount ofthermoreversible polymer (e.g., pluronic F127) in any formulationdescribed herein is about 11% of the total weight of the formulation. Insome embodiments, the amount of thermoreversible polymer (e.g., pluronicF127) in any formulation described herein is about 12% of the totalweight of the formulation. In some embodiments, the amount ofthermoreversible polymer (e.g., pluronic F127) in any formulationdescribed herein is about 13% of the total weight of the formulation. Insome embodiments, the amount of thermoreversible polymer (e.g., pluronicF127) in any formulation described herein is about 14% of the totalweight of the formulation. In some embodiments, the amount ofthermoreversible polymer (e.g., pluronic F127) in any formulationdescribed herein is about 15% of the total weight of the formulation. Insome embodiments, the amount of thermoreversible polymer (e.g., pluronicF127) in any formulation described herein is about 16% of the totalweight of the formulation. In some embodiments, the amount ofthermoreversible polymer (e.g., pluronic F127) in any formulationdescribed herein is about 17% of the total weight of the formulation. Insome embodiments, the amount of thermoreversible polymer (e.g., pluronicF127) in any formulation described herein is about 18% of the totalweight of the formulation. In some embodiments, the amount ofthermoreversible polymer (e.g., pluronic F127) in any formulationdescribed herein is about 19% of the total weight of the formulation. Insome embodiments, the amount of thermoreversible polymer (e.g., pluronicF127) in any formulation described herein is about 20% of the totalweight of the formulation. In some embodiments, the amount ofthermoreversible polymer (e.g., pluronic F127) in any formulationdescribed herein is about 21% of the total weight of the formulation. Insome embodiments, the amount of thermoreversible polymer (e.g., pluronicF127) in any formulation described herein is about 23% of the totalweight of the formulation. In some embodiments, the amount ofthermoreversible polymer (e.g., pluronic F127) in any formulationdescribed herein is about 25% of the total weight of the formulation. Insome embodiments, the amount of thickening agent (e.g., a gelling agent)in any formulation described herein is about 1%, about 5%, about 10%, orabout 15% of the total weight of the formulation. In some embodiments,the amount of thickening agent (e.g., a gelling agent) in anyformulation described herein is about 0.5%, about 1%, about 1.5%, about2%, about 2.5%, about 3%, about 3.5%, about 4%, about 4.5%, or about 5%of the total weight of the formulation.

In some embodiments, the pharmaceutical formulations described hereinare stable with respect to pH over a period of any of at least about 1day, at least about 2 days, at least about 3 days, at least about 4days, at least about 5 days, at least about 6 days, at least about 1week, at least about 2 weeks, at least about 3 weeks, at least about 4weeks, at least about 5 weeks, at least about 6 weeks, at least about 7weeks, at least about 8 weeks, at least about 1 month, at least about 2months, at least about 3 months, at least about 4 months, at least about5 months, or at least about 6 months. In other embodiments, theformulations described herein are stable with respect to pH over aperiod of at least about 1 week. Also described herein are formulationsthat are stable with respect to pH over a period of at least about 1month.

Tonicity Agents

In general, the endolymph has a higher osmolality than the perilymph.For example, the endolymph has an osmolality of about 304 mOsm/kg H₂Owhile the perilymph has an osmolality of about 294 mOsm/kg H2O. Incertain embodiments, tonicity agents are added to the formulationsdescribed herein in an amount as to provide a practical osmolality of anotic formulation of about 100 mOsm/kg to about 1000 mOsm/kg, from about200 mOsm/kg to about 800 mOsm/kg, from about 250 mOsm/kg to about 500mOsm/kg, or from about 250 mOsm/kg to about 350 mOsm/kg or from about280 mOsm/kg to about 320 mOsm/kg. In some embodiments, the formulationsdescribed herein have a practical osmolarity of about 100 mOsm/L toabout 1000 mOsm/L, about 200 mOsm/L to about 800 mOsm/L, about 250mOsm/L to about 500 mOsm/L, about 250 mOsm/L to about 350 mOsm/L, about280 mOsm/L to about 320 mOsm/L or about 250 mOsm/L to about 320 mOsm/L.

In some embodiments, the deliverable osmolarity of any formulationdescribed herein is designed to be isotonic with the targeted oticstructure (e.g., endolymph, perilymph or the like). In specificembodiments, auris compositions described herein are formulated toprovide a delivered perilymph-suitable osmolarity at the target site ofaction of about 250 to about 320 mOsm/L; and preferably about 270 toabout 320 mOsm/L. In specific embodiments, auris compositions describedherein are formulated to provide a delivered perilymph-suitableosmolality at the target site of action of about 250 to about 320mOsm/kg H₂O; or an osmolality of about 270 to about 320 mOsm/kg H2O. Inspecific embodiments, the deliverable osmolarity/osmolality of theformulations (i.e., the osmolarity/osmolality of the formulation in theabsence of gelling or thickening agents (e.g., thermoreversible gelpolymers) is adjusted, for example, by the use of appropriate saltconcentrations (e.g., concentration of potassium or sodium salts) or theuse of tonicity agents which renders the formulationsendolymph-compatible and/or perilymph-compatible (i.e., isotonic withthe endolymph and/or perilymph) upon delivery at the target site. Theosmolarity of a formulation comprising a thermoreversible gel polymer isan unreliable measure due to the association of varying amounts of waterwith the monomeric units of the polymer. The practical osmolarity of aformulation (i.e., osmolarity in the absence of a gelling or thickeningagent (e.g. a thermoreversible gel polymer) is a reliable measure and ismeasured by any suitable method (e.g., freezing point depression method,vapor depression method). In some instances, the formulations describedherein provide a deliverable osmolarity (e.g., at a target site (e.g.,perilymph) that causes minimal disturbance to the environment of theinner ear and causes minimum discomfort (e.g., vertigo and/or nausea) toa mammal upon administration.

In some embodiments, any formulation described herein is isotonic withthe perilymph and/or endolymph. Isotonic formulations are provided bythe addition of a tonicity agent. Suitable tonicity agents include, butare not limited to any pharmaceutically acceptable sugar, salt or anycombinations or mixtures thereof, such as, but not limited to dextrose,glycerin, mannitol, sorbitol, sodium chloride, and other electrolytes.In some embodiments, tonicity agents are non-ototoxic.

Useful auris compositions include one or more salts in an amountrequired to bring osmolality of the composition into an acceptablerange. Such salts include those having sodium, potassium or ammoniumcations and chloride, citrate, ascorbate, borate, phosphate,bicarbonate, sulfate, thiosulfate or bisulfite anions; suitable saltsinclude sodium chloride, potassium chloride, sodium thiosulfate, sodiumbisulfite and ammonium sulfate.

In some embodiments, the formulations described herein have a pH and/orpractical osmolarity as described herein, and have a concentration ofactive pharmaceutical ingredient between about 1 μM and about 10 μM,between about 1 mM and about 100 mM, between about 0.1 mM and about 100mM, between about 0.1 mM and about 100 nM. In some embodiments, theformulations described herein have a pH and/or practical osmolarity asdescribed herein, and have a concentration of active pharmaceuticalingredient between about 0.01%-about 20%, between about 0.01%-about10%., between about 0.01%-about 7.5%, between about 0.01%-6%, betweenabout 0.01-5%, between about 0.1-about 10%, or between about 0.1-about6% of the active ingredient by weight of the formulation. In someembodiments, the formulations described herein have a pH and/orpractical osmolarity as described herein, and have a concentration ofactive pharmaceutical ingredient between about 0.1 and about 70 mg,between about 1 mg and about 70 mg/mL, between about 1 mg and about 50mg/mL, between about 1 mg/mL and about 20 mg/mL, between about 1 mg/mLto about 10 mg/mL, between about 1 mg/mL to about 5 mg/mL, or betweenabout 0.5 mg/mL to about 5 mg/mL of the active agent by volume of theformulation. In some embodiments, the formulations described herein havea pH and/or practical osmolarity as described herein, and have aconcentration of active pharmaceutical ingredient between about 1 μg/mLand about 500 μg/mL, between about 1 μg/mL and about 250 μg/mL, betweenabout 1 μg and about 100 μg/mL, between about 1 μg/mL and about 50μg/mL, or between about 1 μg/mL and about 20 μg/mL of the active agentby volume of the formulation.

Particle Size

Size reduction is used to increase surface area and/or modulateformulation dissolution properties. It is also used to maintain aconsistent average particle size distribution (PSD) (e.g.,micrometer-sized particles, nanometer-sized particles or the like) forany formulation described herein. In some embodiments, any formulationdescribed herein comprises multiparticulates, i.e., a plurality ofparticle sizes (e.g., micronized particles, nano-sized particles,non-sized particles, colloidal particles); i.e., the formulation is amultiparticulate formulation. In some embodiments, any formulationdescribed herein comprises one or more multiparticulate (e.g.,micronized) therapeutic agents. Micronization is a process of reducingthe average diameter of particles of a solid material. Micronizedparticles are from about micrometer-sized in diameter to aboutnanometer-sized in diameter. In some embodiments, the average diameterof particles in a micronized solid is from about 0.5 μm to about 500 μm.In some embodiments, the average diameter of particles in a micronizedsolid is from about 1 μm to about 200 μm. In some embodiments, theaverage diameter of particles in a micronized solid is from about 2 μmto about 100 μm. In some embodiments, the average diameter of particlesin a micronized solid is from about 3 μm to about 50 μm. In someembodiments, a particulate micronized solid comprises particle sizes ofless than about 5 microns, less than about 20 microns and/or less thanabout 100 microns. In some embodiments, the use of particulates (e.g.,micronized particles) of free-radical modulating agent allows forextended and/or sustained release of the free-radical modulating agentfrom any formulation described herein compared to a formulationcomprising non-multiparticulate (e.g., non-micronized) free-radicalmodulating agent. In some instances, formulations containingmultiparticulate (e.g., micronized) free-radical modulating agent areejected from a 1 mL syringe adapted with a 27G needle without anyplugging or clogging.

In some instances, any particle in any formulation described herein is acoated particle (e.g., a coated micronized particle, nano-particle)and/or a microsphere and/or a liposomal particle. Particle sizereduction techniques include, by way of example, grinding, milling(e.g., air-attrition milling (et milling), ball milling), coacervation,complex coacervation, high pressure homogenization, spray drying and/orsupercritical fluid crystallization. In some instances, particles aresized by mechanical impact (e.g., by hammer mills, ball mill and/or pinmills). In some instances, particles are sized via fluid energy (e.g.,by spiral jet mills, loop jet mills, and/or fluidized bed jet mills). Insome embodiments formulations described herein comprise crystallineparticles and/or isotropic particles. In some embodiments, formulationsdescribed herein comprise amorphous particles and/or anisotropicparticles. In some embodiments, formulations described herein comprisetherapeutic agent particles wherein the therapeutic agent is a freebase, or a salt, or a prodrug of a therapeutic agent, or any combinationthereof.

In some embodiments, a formulation described herein comprises one ormore free-radical modulating agents wherein the free-radical modulatingagent comprises nanoparticulates. In some embodiments, a formulationdescribed herein comprises free-radical modulating agent beads (e.g.,deferoxamine beads) that are optionally coated with controlled releaseexcipients. In some embodiments, a formulation described hereincomprises a free-radical modulating agent that is granulated and/orreduced in size and coated with controlled release excipients; thegranulated coated free-radical modulating agent particulates are thenoptionally micronized and/or formulated in any of the compositionsdescribed herein.

In some instances, a combination of a free-radical modulator as aneutral molecule, free acid or free base and/or a salt of thefree-radical modulating agent is used to prepare pulsed release oticagent formulations using the procedures described herein. In someformulations, a combination of a micronized free-radical modulatingagent (and/or salt or prodrug thereof) and coated particles (e.g.,nanoparticles, liposomes, microspheres) is used to prepare pulsedrelease otic agent formulations using any procedure described herein.Alternatively, a pulsed release profile is achieved by solubilizing upto 20% of the delivered dose of the free-radical modulating agent (e.g.,micronized free-radical modulating agent, free base, free acid or saltor prodrug thereof, multiparticulate free-radical modulating agent, freebase, free acid or salt or prodrug thereof) with the aid ofcyclodextrins, surfactants (e.g., poloxamers (407, 338, 188), tween (80,60, 20, 81), PEG-hydrogenated castor oil, cosolvents likeN-methyl-2-Pyrrolidone or the like and preparing pulsed releaseformulations using any procedure described herein.

In specific embodiments, any auris-compatible formulation describedherein comprises one or more micronized pharmaceutical agents (e.g.,free-radical modulating agents). In some of such embodiments, amicronized pharmaceutical agent comprises micronized particles, coated(e.g., with an extended release coat) micronized particles, or acombination thereof. In some of such embodiments, a micronizedpharmaceutical agent comprising micronized particles, coated micronizedparticles, or a combination thereof, comprises a free-radical modulatoras a neutral molecule, a free acid, a free base, a salt, a prodrug orany combination thereof. In certain embodiments, a pharmaceuticalcomposition described herein comprises a free-radical modulator as amicronized powder. In certain embodiments, a pharmaceutical compositiondescribed herein comprises a free-radical modulator in the form of amicronized free-radical modulating agent powder.

The multiparticulates and/or micronized free-radical modulating agentsdescribed herein are delivered to an auris structure (e.g., inner ear)by means of any type of matrix including solid, liquid or gel matrices.In some embodiments, the multiparticulates and/or micronizedfree-radical modulating agents described herein are delivered to anauris structure (e.g., inner ear) by means of any type of matrixincluding solid, liquid or gel matrices via intratympanic injection.

Tunable Release Characteristics

The release of active agent from any formulation, composition or devicedescribed herein is optionally tunable to the desired releasecharacteristics. In some embodiments, a composition described herein isa solution that is substantially free of gelling components. In suchinstances, the composition provides essentially immediate release of anactive agent. In some of such embodiments, the composition is useful inperfusion of otic structures, e.g., during surgery.

In some embodiments, a composition described herein is a solution thatis substantially free of gelling components and comprises micronizedotic agent (e.g., a corticosteroid, a free-radical modulator or thelike). In some of such embodiments, the composition provides release ofan active agent from about 2 days to about 4 days.

In some embodiments, a composition described herein comprises a gellingagent (e.g., poloxamer 407) and provides release of an active agent overa period of from about 1 day to about 3 days. In some embodiments, acomposition described herein comprises a gelling agent (e.g., poloxamer407) and provides release of an active agent over a period of from about1 day to about 5 days. In some embodiments, a composition describedherein comprises a gelling agent (e.g., poloxamer 407) and providesrelease of an active agent over a period of from about 2 days to about 7days.

In some embodiments, a composition described herein comprises a gellingagent (e.g., poloxamer 407) in combination with micronized otic agentand provides extended sustained release over a longer period of time. Insome embodiments, a composition described herein comprises about 14-17%of a gelling agent (e.g., poloxamer 407) and micronized otic agent, andprovides extended sustained release over a period of from about 1 weekto about 3 weeks. In some embodiments, a composition described hereincomprises about 18-21% of a gelling agent (e.g., poloxamer 407) andmicronized otic agent, and provides extended sustained release over aperiod of from about 3 weeks to about 6 weeks.

Accordingly, the amount of gelling agent in a composition, and theparticle size of an otic agent are tunable to the desired releaseprofile of an otic agent from the composition.

As described herein, compositions comprising micronized otic agentsprovide extended release over a longer period of time compared tocompositions comprising non-micronized otic agents. In some instances,the micronized otic agent provides a steady supply (e.g., +/−20%) ofactive agent via slow degradation and serves as a depot for the activeagent; such a depot effect increases residence time of the otic agent inthe ear. In specific embodiments, selection of an appropriate particlesize of the active agent (e.g., micronized active agent) in combinationwith the amount of gelling agent in the composition provides tunableextended release characteristics that allow for release of an activeagent over a period of hours, days, weeks or months.

In some embodiments, the viscosity of any formulation described hereinis designed to provide a suitable rate of release from an auriscompatible gel. In some embodiments, the concentration of a thickeningagent (e.g., gelling components such as polyoxyethylene-polyoxypropylenecopolymers) allows for a tunable mean dissolution time (MDT). The MDT isinversely proportional to the release rate of an active agent from acomposition or device described herein. Experimentally, the releasedotic agent is optionally fitted to the Korsmeyer-Peppas equation

$\frac{Q}{Q_{\alpha}} = {{kt}^{n} + b}$

where Q is the amount of otic agent released at time t, Qα is theoverall released amount of otic agent, k is a release constant of thenth order, n is a dimensionless number related to the dissolutionmechanism and b is the axis intercept, characterizing the initial burstrelease mechanism wherein n=1 characterizes an erosion controlledmechanism. The mean dissolution time (MDT) is the sum of differentperiods of time the drug molecules stay in the matrix before release,divided by the total number of molecules and is optionally calculatedby:

${M\; D\; T} = \frac{{nk}^{{- 1}/n}}{n + 1}$

For example, a linear relationship between the mean dissolution time(MDT) of a composition or device and the concentration of the gellingagent (e.g., poloxamer) indicates that the otic agent is released due tothe erosion of the polymer gel (e.g., poloxamer) and not via diffusion.In another example, a non-linear relationship indicates release of oticagent via a combination of diffusion and/or polymer gel degradation. Inanother example, a faster gel elimination time course of a compositionor device (a faster release of active agent) indicates lower meandissolution time (MDT). The concentration of gelling components and/oractive agent in a composition are tested to determine suitableparameters for MDT. In some embodiments, injection volumes are alsotested to determine suitable parameters for preclinical and clinicalstudies. The gel strength and concentration of the active agent affectsrelease kinetics of an otic agent from the composition. At low poloxamerconcentration, elimination rate is accelerated (MDT is lower). Anincrease in otic agent concentration in the composition or deviceprolongs residence time and/or MDT of the otic agent in the ear.

In some embodiments, the MDT for poloxamer from a composition or devicedescribed herein is at least 6 hours. In some embodiments, the MDT forpoloxamer from a composition or device described herein is at least 10hours.

In some embodiments, the MDT for an active agent from a composition ordevice described herein is from about 30 hours to about 48 hours. Insome embodiments, the MDT for an active agent from a composition ordevice described herein is from about 30 hours to about 96 hours. Insome embodiments, the MDT for an active agent from a composition ordevice described herein is from about 30 hours to about 1 week. In someembodiments, the MDT for a composition or device described herein isfrom about 1 week to about 6 weeks.

In some embodiments, the mean residence time (MRT) for an active agentin a composition or device described herein is from about 20 hours toabout 48 hours. In some embodiments, the MRT for an active agent from acomposition or device described herein is from about 20 hours to about96 hours. In some embodiments, the MRT for an active agent from acomposition or device described herein is from about 20 hours to about 1week.

In some embodiments, the MRT for an active agent is about 20 hours. Insome embodiments, the MRT for an active agent is about 30 hours. In someembodiments, the MRT for an active agent is about 40 hours. In someembodiments, the MRT for an active agent is about 50 hours. In someembodiments, the MRT for an active agent is about 60 hours. In someembodiments, the MRT for an active agent is about 70 hours. In someembodiments, the MRT for an active agent is about 80 hours. In someembodiments, the MRT for an active agent is about 90 hours. In someembodiments, the MRT for an active agent is about 1 week. In someembodiments, the MRT for an active agent is about 90 hours. In someembodiments, the MRT for a composition or device described herein isfrom about 1 week to about 6 weeks. In some embodiments, the MRT for anactive agent is about 1 week. In some embodiments, the MRT for an activeagent is about 2 weeks. In some embodiments, the MRT for an active agentis about 3 weeks. In some embodiments, the MRT for an active agent isabout 4 weeks. In some embodiments, the MRT for an active agent is about5 weeks. In some embodiments, the MRT for an active agent is about 6weeks. In some embodiments, the MRT for an active agent is about 7weeks. The half life of an otic agent and mean residence time of theotic agent are determined for each formulation by measurement ofconcentration of the otic agent in the perilymph using proceduresdescribed herein.

In certain embodiments, any controlled release otic formulationdescribed herein increases the exposure of an otic agent and increasesthe Area Under the Curve (AUC) in otic fluids (e.g., endolymph and/orperilymph) by about 30%, about 40%, about 50%, about 60%, about 70%,about 80% or about 90% compared to a formulation that is not acontrolled release otic formulation. In certain embodiments, anycontrolled release otic formulation described herein increases theexposure time of an otic agent and decreases the Cmax in otic fluids(e.g., endolymph and/or perilymph) by about 40%, about 30%, about 20%,or about 10%, compared to a formulation that is not a controlled releaseotic formulation. In certain embodiments, any controlled release oticformulation described herein alters (e.g. reduces) the ratio of Cmax toCmin compared to a formulation that is not a controlled release oticformulation. In certain embodiments, any controlled release oticformulation described herein increases the exposure of an otic agent andincreases the length of time that the concentration of an otic agent isabove Cmin by about 30%, about 40%, about 50%, about 60%, about 70%,about 80% or about 90% compared to a formulation that is not acontrolled release otic formulation. In certain instances, controlledrelease formulations described herein delay the time to Cmax. In certaininstances, the controlled steady release of a drug prolongs the time theconcentration of the drug will stay above the Cmin. In some embodiments,auris compositions described herein prolong the residence time of a drugin the inner ear and provide a stable drug exposure profile. In someinstances, an increase in concentration of an active agent in thecomposition saturates the clearance process and allows for a more rapidand stable steady state to be reached.

In certain instances, once drug exposure (e.g., concentration in theendolymph or perilymph) of a drug reaches steady state, theconcentration of the drug in the endolymph or perilymph stays at orabout the therapeutic dose for an extended period of time (e.g., oneday, 2 days, 3 days, 4 days, 5 days, 6 days, or 1 week, 3 weeks, 6weeks, 2 months). In some embodiments, the steady state concentration ofactive agent released from a controlled release formulation describedherein is about 5 to about 20 times the steady state concentration of anactive agent released from a formulation that is not a controlledrelease formulation. In some embodiments, the steady state concentrationof active agent released from a controlled release formulation describedherein is about 20 to about 50 times the steady state concentration ofan active agent released from a formulation that is not a controlledrelease formulation. FIG. 5 shows predicted tunable release of an activeagent from four compositions.

Pharmaceutical Formulations

Provided herein are pharmaceutical compositions or devices that includeat least one free-radical modulating agent and a pharmaceuticallyacceptable diluent(s), excipient(s), or carrier(s). In some embodiments,the pharmaceutical compositions include other medicinal orpharmaceutical agents, carriers, adjuvants, such as preserving,stabilizing, wetting or emulsifying agents, solution promoters, saltsfor regulating the osmotic pressure, and/or buffers. In otherembodiments, the pharmaceutical compositions also contain othertherapeutic substances.

In some embodiments, the compositions or devices described hereininclude a dye to help enhance the visualization of the gel when applied.In some embodiments, dyes that are compatible with the auris-acceptablecompositions or devices described herein include Evans blue (e.g., 0.5%of the total weight of an otic formulation), Methylene blue (e.g., 1% ofthe total weight of an otic formulation), Isosulfan blue (e.g., 1% ofthe total weight of an otic formulation), Trypan blue (e.g., 0.15% ofthe total weight of an otic formulation), and/or indocyanine green(e.g., 25 mg/vial). Other common dyes, e.g, FD&C red 40, FD&C red 3,FD&C yellow 5, FD&C yellow 6, FD&C blue 1, FD&C blue2, FD&C green 3,fluorescence dyes (e.g., Fluorescein isothiocyanate, rhodamine, AlexaFluors, DyLight Fluors) and/or dyes that are visualizable in conjunctionwith non-invasive imaging techniques such as MRI, CAT scans, PET scansor the like. Gadolinium-based MRI dyes, iodine-base dyes, barium-baseddyes or the like are also contemplated for use with any otic formulationdescribed herein. Other dyes that are compatible with any formulation orcomposition described herein are listed in the Sigma-Aldrich catalogunder dyes (which is included herein by reference for such disclosure).

In some embodiments, mechanical or imaging devices are used to monitoror survey the hearing, balance or other auris disorder. For example,magnetic resonance imaging (MRI) devices are specifically contemplatedwithin the scope of the embodiments, wherein the MRI devices (forexample, 3 Tesla MRI devices) are capable of evaluating diseaseprogression, and subsequent treatment with the pharmaceuticalformulations disclosed herein. Gadolinium-based dyes, iodine-base dyes,barium-based dyes or the like are also contemplated for use with anyauris-compatible composition or device described herein and/or with anymechanical or imaging devices described herein. In certain embodiments,gadolinium hydrate is used in combination with MRI and/or anypharmaceutical composition or device described herein to evaluatedisease severity (e.g., size of endolymphatic hydrops), formulationpenetration into the inner ear, and/or therapeutic effectiveness of thepharmaceutical formulations/devices in the otic diseases describedherein (e.g., sensorineural hearing loss).

Any pharmaceutical composition or device described herein isadministered by locating the composition or device in contact with thecrista fenestrae cochlea, the round window, the tympanic cavity, thetympanic membrane, the auris media or the auris externa.

In one specific embodiment of the auris-acceptable controlled releasefree-radical modulating agent pharmaceutical formulations describedherein, the free-radical modulating agent is provided in a gel matrix,also referred to herein as “auris acceptable gel formulations,” “aurisinterna-acceptable gel formulations,” “auris media-acceptable gelformulations,” “auris externa-acceptable gel formulations”, “auris gelformulations” or variations thereof. All of the components of the gelformulation must be compatible with the targeted auris structure.Further, the gel formulations provide controlled release of thefree-radical modulating agent to the desired site within the targetedauris structure; in some embodiments, the gel formulation also has animmediate or rapid release component for delivery of the free-radicalmodulating agent to the desired target site. In other embodiments, thegel formulation has a sustained release component for delivery of thefree-radical modulating agent. In some embodiments, the gel formulationcomprises a multiparticulate (e.g., micronized) free-radical modulatingagent. In some embodiments, the auris gel formulations arebiodegradeable. In other embodiments, the auris gel formulations includea mucoadhesive excipient to allow adhesion to the external mucous layerof the round window membrane. In yet other embodiments, the auris gelformulations include a penetration enhancer excipient.

In further embodiments, the auris gel formulation contains a viscosityenhancing agent sufficient to provide a viscosity of between about 500and 1,000,000 centipoise, between about 750 and 1,000,000 centipoise;between about 1000 and 1,000,000 centipoise; between about 1000 and400,000 centipoise; between about 2000 and 100,000 centipoise; betweenabout 3000 and 50,000 centipoise; between about 4000 and 25,000centipoise; between about 5000 and 20,000 centipoise; or between about6000 and 15,000 centipoise. In some embodiments, the auris gelformulation contains a viscosity enhancing agent sufficient to provide aviscosity of between about 50,0000 and 1,000,000 centipoise.

In some embodiments, the compositions or devices described herein arelow viscosity compositions or devices at body temperature. In someembodiments, low viscosity compositions or devices contain from about 1%to about 10% of a viscosity enhancing agent (e.g., gelling componentssuch as polyoxyethylene-polyoxypropylene copolymers). In someembodiments, low viscosity compositions or devices contain from about 2%to about 10% of a viscosity enhancing agent (e.g., gelling componentssuch as polyoxyethylene-polyoxypropylene copolymers). In someembodiments, low viscosity compositions or devices contain from about 5%to about 10% of a viscosity enhancing agent (e.g., gelling componentssuch as polyoxyethylene-polyoxypropylene copolymers). In someembodiments, low viscosity compositions or devices are substantiallyfree of a viscosity enhancing agent (e.g., gelling components such aspolyoxyethylene-polyoxypropylene copolymers). In some embodiments, a lowviscosity free-radical modulating agent composition or device describedherein provides an apparent viscosity of from about 100 cP to about10,000 cP. In some embodiments, a low viscosity free-radical modulatingagent composition or device described herein provides an apparentviscosity of from about 500 cP to about 10,000 cP. In some embodiments,a low viscosity free-radical modulating agent composition or devicedescribed herein provides an apparent viscosity of from about 1000 cP toabout 10,000 cP. In some of such embodiments, a low viscosityfree-radical modulating agent composition or device is administered incombination with an external otic intervention, e.g., a surgicalprocedure including but not limited to middle ear surgery, inner earsurgery, typanostomy, cochleostomy, labyrinthotomy, mastoidectomy,stapedectomy, stapedotomy, endolymphatic sacculotomy or the like. Insome of such embodiments, a low viscosity free-radical modulating agentcomposition or device is administered during an otic intervention. Inother such embodiments, a low viscosity free-radical modulating agentcomposition or device is administered before the otic intervention.

In some embodiments, the compositions or devices described herein arehigh viscosity compositions or devices at body temperature. In someembodiments, high viscosity compositions or devices contain from about10% to about 25% of a viscosity enhancing agent (e.g., gellingcomponents such as polyoxyethylene-polyoxypropylene copolymers). In someembodiments, high viscosity compositions or devices contain from about14% to about 22% of a viscosity enhancing agent (e.g., gellingcomponents such as polyoxyethylene-polyoxypropylene copolymers). In someembodiments, high viscosity compositions or devices contain from about15% to about 21% of a viscosity enhancing agent (e.g., gellingcomponents such as polyoxyethylene-polyoxypropylene copolymers). In someembodiments, a high viscosity free-radical modulating agent compositionor device described herein provides an apparent viscosity of from about100,000 cP to about 1,000,000 cP. In some embodiments, a high viscosityfree-radical modulating agent composition or device described hereinprovides an apparent viscosity of from about 150,000 cP to about 500,000cP. In some embodiments, a high viscosity free-radical modulating agentcomposition or device described herein provides an apparent viscosity offrom about 250,000 cP to about 500,000 cP. In some of such embodiments,a high viscosity composition or device is a liquid at room temperatureand gels at about between room temperature and body temperature(including an individual with a serious fever, e.g., up to about 42°C.). In some embodiments, a free-radical modulating agent high viscositycomposition or device is administered as monotherapy for treatment of anotic disease or condition described herein. In some embodiments, afree-radical modulating agent high viscosity composition or device isadministered in combination with an external otic intervention, e.g., asurgical procedure including but not limited to middle ear surgery,inner ear surgery, typanostomy, cochleostomy, labyrinthotomy,mastoidectomy, stapedectomy, stapedotomy, endolymphatic sacculotomy orthe like. In some of such embodiments, a high viscosity free-radicalmodulating agent composition or device is administered after the oticintervention. In other such embodiments, a high viscosity free-radicalmodulating agent composition or device is administered before the oticintervention.

In other embodiments, the auris interna pharmaceutical formulationsdescribed herein further provide an auris-acceptable hydrogel; in yetother embodiments, the auris pharmaceutical formulations provide anauris-acceptable microsphere or microparticle; in still otherembodiments, the auris pharmaceutical formulations provide anauris-acceptable liposome. In some embodiments, the auris pharmaceuticalformulations provide an auris-acceptable foam; in yet other embodiments,the auris pharmaceutical formulations provide an auris-acceptable paint;in still further embodiments, the auris pharmaceutical formulationsprovide an auris-acceptable in situ forming spongy material. In someembodiments, the auris pharmaceutical formulations provide anauris-acceptable solvent release gel. In some embodiments, the aurispharmaceutical formulations provide an actinic radiation curable gel.Further embodiments include a thermoreversible gel in the aurispharmaceutical formulation, such that upon preparation of the gel atroom temperature or below, the formulation is a fluid, but uponapplication of the gel into or near the auris interna and/or auris mediatarget site, including the tympanic cavity, round window membrane or thecrista fenestrae cochleae, the auris-pharmaceutical formulation stiffensor hardens into a gel-like substance.

In further or alternative embodiments, the auris gel formulations arecapable of being administered on or near the round window membrane viaintratympanic injection. In other embodiments, the auris gelformulations are administered on or near the round window or the cristafenestrae cochleae through entry via a post-auricular incision andsurgical manipulation into or near the round window or the cristafenestrae cochleae area. Alternatively, the auris gel formulation isapplied via syringe and needle, wherein the needle is inserted throughthe tympanic membrane and guided to the area of the round window orcrista fenestrae cochleae. The auris gel formulations are then depositedon or near the round window or crista fenestrae cochleae for localizedtreatment of autoimmune otic disorders. In other embodiments, the aurisgel formulations are applied via microcatheters implanted into thepatient, and in yet further embodiments the formulations areadministered via a pump device onto or near the round window membrane.In still further embodiments, the auris gel formulations are applied ator near the round window membrane via a microinjection device. In yetother embodiments, the auris gel formulations are applied in thetympanic cavity. In some embodiments, the auris gel formulations areapplied on the tympanic membrane. In still other embodiments, the aurisgel formulations are applied onto or in the auditory canal.

In further specific embodiments, any pharmaceutical composition ordevice described herein comprises a multiparticulate free-radicalmodulating agent in a liquid matrix (e.g., a liquid composition forintratympanic injection, or otic drops). In certain embodiments, anypharmaceutical composition described herein comprises a multiparticulatefree-radical modulating agent in a solid matrix.

Controlled Release Formulations

In general, controlled release drug formulations impart control over therelease of drug with respect to site of release and time of releasewithin the body. As discussed herein, controlled release refers toimmediate release, delayed release, sustained release, extended release,variable release, pulsatile release and bi-modal release. Manyadvantages are offered by controlled release. First, controlled releaseof a pharmaceutical agent allows less frequent dosing and thus minimizesrepeated treatment. Second, controlled release treatment results in moreefficient drug utilization and less of the compound remains as aresidue. Third, controlled release offers the possibility of localizeddrug delivery by placement of a delivery device or formulation at thesite of disease. Still further, controlled release offers theopportunity to administer and release two or more different drugs, eachhaving a unique release profile, or to release the same drug atdifferent rates or for different durations, by means of a single dosageunit.

Accordingly, one aspect of the embodiments disclosed herein is toprovide a controlled release free-radical modulating agentauris-acceptable composition or device for the treatment of tinnitus,balance disorders and/or disease caused by free-radical induced damageor oxidative damage. The controlled release aspect of the compositionsand/or formulations and/or devices disclosed herein is imparted througha variety of agents, including but not limited to excipients, agents ormaterials that are acceptable for use in the auris interna or other oticstructure. By way of example only, such excipients, agents or materialsinclude an auris-acceptable polymer, an auris-acceptable viscosityenhancing agent, an auris-acceptable gel, an auris-acceptable paint, anauris-acceptable foam, an auris-acceptable xerogel, an auris-acceptablemicrosphere or microparticle, an auris-acceptable hydrogel, anauris-acceptable in situ forming spongy material, an auris-acceptableactinic radiation curable gel, an auris-acceptable solvent release gel,an auris-acceptable liposome, an auris-acceptable nanocapsule ornanosphere, an auris-acceptable thermoreversible gel, or combinationsthereof.

Auris-Acceptable Gels

Gels, sometimes referred to as jellies, have been defined in variousways. For example, the United States Pharmacopoeia defines gels assemisolid systems consisting of either suspensions made up of smallinorganic particles or large organic molecules interpenetrated by aliquid. Gels include a single-phase or a two-phase system. Asingle-phase gel consists of organic macromolecules distributeduniformly throughout a liquid in such a manner that no apparentboundaries exist between the dispersed macromolecules and the liquid.Some single-phase gels are prepared from synthetic macromolecules (e.g.,carbomer) or from natural gums, (e.g., tragacanth). In some embodiments,single-phase gels are generally aqueous, but will also be made usingalcohols and oils. Two-phase gels consist of a network of small discreteparticles.

Gels can also be classified as being hydrophobic or hydrophilic. Incertain embodiments, the base of a hydrophobic gel consists of a liquidparaffin with polyethylene or fatty oils gelled with colloidal silica,or aluminum or zinc soaps. In contrast, the base of hydrophobic gelsusually consists of water, glycerol, or propylene glycol gelled with asuitable gelling agent (e.g., tragacanth, starch, cellulose derivatives,carboxyvinylpolymers, and magnesium-aluminum silicates). In certainembodiments, the rheology of the compositions or devices disclosedherein is pseudo plastic, plastic, thixotropic, or dilatant.

In one embodiment the enhanced viscosity auris-acceptable formulationdescribed herein is not a liquid at room temperature. In certainembodiments, the enhanced viscosity formulation is characterized by aphase transition between room temperture and body temperature (includingan individual with a serious fever, e.g., up to about 42° C.). In someembodiments, the phase transition occurs at 1° C. below bodytemperature, at 2° C. below body temperature, at 3° C. below bodytemperture, at 4° C. below body temperature, at 6° C. below bodytemperature, at 8° C. below body temperature, or at 10° C. below bodytemperature. In some embodiments, the phase transition occurs at about15° C. below body temperature, at about 20° C. below body temperature orat about 25° C. below body temperature. In specific embodiments, thegelation temperature (Tgel) of a formulation described herein is about20° C., about 25° C., or about 30° C. In certain embodiments, thegelation temperature (Tgel) of a formulation described herein is about35° C., or about 40° C. In one embodiment, administration of anyformulation described herein at about body temperature reduces orinhibits vertigo associated with intratympanic administration of oticformulations. Included within the definition of body temperature is thebody temperature of a healthy individual, or an unhealthy individual,including an individual with a fever (up to ˜42° C.). In someembodiments, the pharmaceutical compositions or devices described hereinare liquids at about room temperature and are administered at or aboutroom temperature, reducing or ameliorating side effects such as, forexample, vertigo.

Polymers composed of polyoxypropylene and polyoxyethylene formthermoreversible gels when incorporated into aqueous solutions. Thesepolymers have the ability to change from the liquid state to the gelstate at temperatures close to body temperture, therefore allowinguseful formulations that are applied to the targeted auris structure(s).The liquid state-to-gel state phase transition is dependent on thepolymer concentration and the ingredients in the solution.

Poloxamer 407 (PF-127) is a nonionic surfactant composed ofpolyoxyethylene-polyoxypropylene copolymers. Other poloxamers include188 (F-68 grade), 237 (F-87 grade), 338 (F-108 grade). Aqueous solutionsof poloxamers are stable in the presence of acids, alkalis, and metalions. PF-127 is a commercially availablepolyoxyethylene-polyoxypropylene triblock copolymer of general formulaE106 P70 E106, with an average molar mass of 13,000. The polymer can befurther purified by suitable methods that will enhance gelationproperties of the polymer. It contains approximately 70% ethylene oxide,which accounts for its hydrophilicity. It is one of the series ofpoloxamer ABA block copolymers, whose members share the chemical formulashown below.

PF-127 is of particular interest since concentrated solutions (>20% w/w)of the copolymer are transformed from low viscosity transparentsolutions to solid gels on heating to body temperature. This phenomenon,therefore, suggests that when placed in contact with the body, the gelpreparation will form a semi-solid structure and a sustained releasedepot. Furthermore, PF-127 has good solubilizing capacity, low toxicityand is, therefore, considered a good medium for drug delivery systems.

In an alternative embodiment, the thermogel is a PEG-PLGA-PEG triblockcopolymer (Jeong et al, Nature (1997), 388:860-2; Jeong et al, J.Control. Release (2000), 63:155-63; Jeong et al, Adv. Drug Delivery Rev.(2002), 54:37-51). The polymer exhibits sol-gel behavior over aconcentration of about 5% w/w to about 40% w/w. Depending on theproperties desired, the lactide/glycolide molar ratio in the PLGAcopolymer ranges from about 1:1 to about 20:1. The resulting coploymersare soluble in water and form a free-flowing liquid at room temperature,but form a hydrogel at body temperature. A commercially availablePEG-PLGA-PEG triblock copolymer is RESOMER RGP t50106 manufactured byBoehringer Ingelheim. This material is composed of a PGLA copolymer of50:50 poly(DL-lactide-co-glycolide) and is 10% w/w of PEG and has amolecular weight of about 6000.

ReGel® is a tradename of MacroMed Incorporated for a class of lowmolecular weight, biodegradable block copolymers having reverse thermalgelation properties as described in U.S. Pat. Nos. 6,004,573, 6,117,949,6,201,072, and 6,287,588. It also includes biodegradable polymeric drugcarriers disclosed in pending U.S. patent application Ser. Nos.09/906,041, 09/559,799 and 10/919,603. The biodegradable drug carriercomprises ABA-type or BAB-type triblock copolymers or mixtures thereof,wherein the A-blocks are relatively hydrophobic and comprisebiodegradable polyesters or poly(orthoester)s, and the B-blocks arerelatively hydrophilic and comprise polyethylene glycol (PEG), saidcopolymers having a hydrophobic content of between 50.1 to 83% by weightand a hydrophilic content of between 17 to 49.9% by weight, and anoverall block copolymer molecular weight of between 2000 and 8000Daltons. The drug carriers exhibit water solubility at temperaturesbelow normal mammalian body temperatures and undergo reversible thermalgelation to then exist as a gel at temperatures equal to physiologicalmammalian body temperatures. The biodegradable, hydrophobic A polymerblock comprises a polyester or poly(ortho ester), in which the polyesteris synthesized from monomers selected from the group consisting ofD,L-lactide, D-lactide, L-lactide, D,L-lactic acid, D-lactic acid,L-lactic acid, glycolide, glycolic acid, ε-caprolactone,ε-hydroxyhexanoic acid, γ-butyrolactone, γ-hydroxybutyric acid,δ-valerolactone, δ-hydroxyvaleric acid, hydroxybutyric acids, malicacid, and copolymers thereof and having an average molecular weight ofbetween about 600 and 3000 Daltons. The hydrophilic B-block segment ispreferably polyethylene glycol (PEG) having an average molecular weightof between about 500 and 2200 Daltons.

Additional biodegradable thermoplastic polyesters include AtriGel®(provided by Atrix Laboratories, Inc.) and/or those disclosed, e.g., inU.S. Pat. Nos. 5,324,519; 4,938,763; 5,702,716; 5,744,153; and5,990,194; wherein the suitable biodegradable thermoplastic polyester isdisclosed as a thermoplastic polymer. Examples of suitable biodegradablethermoplastic polyesters include polylactides, polyglycolides,polycaprolactones, copolymers thereof, terpolymers thereof, and anycombinations thereof. In some such embodiments, the suitablebiodegradable thermoplastic polyester is a polylactide, a polyglycolide,a copolymer thereof, a terpolymer thereof, or a combination thereof. Inone embodiment, the biodegradable thermoplastic polyester is 50/50poly(DL-lactide-co-glycolide) having a carboxy terminal group; ispresent in about 30 wt. % to about 40 wt. % of the composition; and hasan average molecular weight of about 23,000 to about 45,000.Alternatively, in another embodiment, the biodegradable thermoplasticpolyester is 75/25 poly(DL-lactide-co-glycolide) without a carboxyterminal group; is present in about 40 wt. % to about 50 wt. % of thecomposition; and has an average molecular weight of about 15,000 toabout 24,000. In further or alternative embodiments, the terminal groupsof the poly(DL-lactide-co-glycolide) are either hydroxyl, carboxyl, orester depending upon the method of polymerization. Polycondensation oflactic or glycolic acid provides a polymer with terminal hydroxyl andcarboxyl groups. Ring-opening polymerization of the cyclic lactide orglycolide monomers with water, lactic acid, or glycolic acid providespolymers with the same terminal groups. However, ring-opening of thecyclic monomers with a monofunctional alcohol such as methanol, ethanol,or 1-dodecanol provides a polymer with one hydroxyl group and one esterterminal groups. Ring-opening polymerization of the cyclic monomers witha diol such as 1,6-hexanediol or polyethylene glycol provides a polymerwith only hydroxyl terminal groups.

Since the polymer systems of thermoreversible gels dissolve morecompletely at reduced temperatures, methods of solubilization includeadding the required amount of polymer to the amount of water to be usedat reduced temperatures. Generally after wetting the polymer by shaking,the mixture is capped and placed in a cold chamber or in a thermostaticcontainer at about 0-10° C. in order to dissolve the polymer. Themixture is stirred or shaken to bring about a more rapid dissolution ofthe thermoreversible gel polymer. The free-radical modulating agent andvarious additives such as buffers, salts, and preservatives aresubsequently added and dissolved. In some instances the free-radicalmodulating agent and/or other pharmaceutically active agent is suspendedif it is insoluble in water. The pH is modulated by the addition ofappropriate buffering agents. round window membrane mucoadhesivecharacteristics are optionally imparted to a thermoreversible gel byincorporation of round window membrane mucoadhesive carbomers, such asCarbopol® 934P, to the composition (Majithiya et al, AAPS PharmSciTech(2006), 7(3), p. E1; EP0551626, both of which is incorporated herein byreference for such disclosure).

In one embodiment are auris-acceptable pharmaceutical gel formulationswhich do not require the use of an added viscosity enhancing agent. Suchgel formulations incorporate at least one pharmaceutically acceptablebuffer. In one aspect is a gel formulation comprising a free-radicalmodulator and a pharmaceutically acceptable buffer. In anotherembodiment, the pharmaceutically acceptable excipient or carrier is agelling agent.

In other embodiments, useful free-radical modulating agentauris-acceptable pharmaceutical formulations also include one or more pHadjusting agents or buffering agents to provide an endolymph orperilymph suitable pH. Suitable pH adjusting agents or buffers include,but are not limited to acetate, bicarbonate, ammonium chloride, citrate,phosphate, pharmaceutically acceptable salts thereof and combinations ormixtures thereof. Such pH adjusting agents and buffers are included inan amount required to maintain pH of the composition between a pH ofabout 5 and about 9, in one embodiment a pH between about 6.5 to about7.5, and in yet another embodiment at a pH of about 6.5, 6.6, 6.7, 6.8,6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5. In one embodiment, when one or morebuffers are utilized in the formulations of the present disclosure, theyare combined, e.g., with a pharmaceutically acceptable vehicle and arepresent in the final formulation, e.g., in an amount ranging from about0.1% to about 20%, from about 0.5% to about 10%. In certain embodimentsof the present disclosure, the amount of buffer included in the gelformulations are an amount such that the pH of the gel formulation doesnot interfere with the auris media or auris interna's natural bufferingsystem, or does not interfere with the natural pH of the endolymph orperilymph: depending on where in the cochlea the free-radical modulatingagent formulation is targeted. In some embodiments, from about 10 μM toabout 200 mM concentration of a buffer is present in the gelformulation. In certain embodiments, from about a 5 mM to about a 200 mMconcentration of a buffer is present. In certain embodiments, from abouta 20 mM to about a 100 mM concentration of a buffer is present. In oneembodiment is a buffer such as acetate or citrate at slightly acidic pH.In one embodiment the buffer is a sodium acetate buffer having a pH ofabout 4.5 to about 6.5. In one embodiment the buffer is a sodium citratebuffer having a pH of about 5.0 to about 8.0, or about 5.5 to about 7.0.

In an alternative embodiment, the buffer used istris(hydroxymethyl)aminomethane, bicarbonate, carbonate or phosphate atslightly basic pH. In one embodiment, the buffer is a sodium bicarbonatebuffer having a pH of about 6.5 to about 8.5, or about 7.0 to about 8.0.In another embodiment the buffer is a sodium phosphate dibasic bufferhaving a pH of about 6.0 to about 9.0.

Also described herein are controlled release formulations or devicescomprising a free-radical modulator and a viscosity enhancing agent.Suitable viscosity-enhancing agents include by way of example only,gelling agents and suspending agents. In one embodiment, the enhancedviscosity formulation does not include a buffer. In other embodiments,the enhanced viscosity formulation includes a pharmaceuticallyacceptable buffer. Sodium chloride or other tonicity agents areoptionally used to adjust tonicity, if necessary.

By way of example only, the auris-acceptable viscosity agent includehydroxypropyl methylcellulose, hydroxyethyl cellulose,polyvinylpyrrolidone, carboxymethyl cellulose, polyvinyl alcohol, sodiumchondroitin sulfate, sodium hyaluronate. Other viscosity enhancingagents compatible with the targeted auris structure include, but are notlimited to, acacia (gum arabic), agar, aluminum magnesium silicate,sodium alginate, sodium stearate, bladderwrack, bentonite, carbomer,carrageenan, Carbopol, xanthan, cellulose, microcrystalline cellulose(MCC), ceratonia, chitin, carboxymethylated chitosan, chondrus,dextrose, furcellaran, gelatin, Ghatti gum, guar gum, hectorite,lactose, sucrose, maltodextrin, mannitol, sorbitol, honey, maize starch,wheat starch, rice starch, potato starch, gelatin, sterculia gum,xanthum gum, gum tragacanth, ethyl cellulose, ethylhydroxyethylcellulose, ethylmethyl cellulose, methyl cellulose, hydroxyethylcellulose, hydroxyethylmethyl cellulose, hydroxypropyl cellulose,poly(hydroxyethyl methacrylate), oxypolygelatin, pectin, polygeline,povidone, propylene carbonate, methyl vinyl ether/maleic anhydridecopolymer (PVM/MA), poly(methoxyethyl methacrylate),poly(methoxyethoxyethyl methacrylate), hydroxypropyl cellulose,hydroxypropylmethyl-cellulose (HPMC), sodium carboxymethyl-cellulose(CMC), silicon dioxide, polyvinylpyrrolidone (PVP: povidone), Splenda®(dextrose, maltodextrin and sucralose) or combinations thereof. Inspecific embodiments, the viscosity-enhancing excipient is a combinationof MCC and CMC. In another embodiment, the viscosity-enhancing agent isa combination of carboxymethylated chitosan, or chitin, and alginate.The combination of chitin and alginate with the free-radical modulatingagents disclosed herein acts as a controlled release formulation,restricting the diffusion of the free-radical modulating agents from theformulation. Moreover, the combination of carboxymethylated chitosan andalginate is optionally used to assist in increasing the permeability ofthe free-radical modulating agents through the round window membrane.

In some embodiments is an enhanced viscosity formulation, comprisingfrom about 0.1 mM and about 100 mM of a free-radical modulating agent, apharmaceutically acceptable viscosity agent, and water for injection,the concentration of the viscosity agent in the water being sufficientto provide a enhanced viscosity formulation with a final viscosity fromabout 100 to about 100,000 cP. In certain embodiments, the viscosity ofthe gel is in the range from about 100 to about 50,000 cP, about 100 cPto about 1,000 cP, about 500 cP to about 1500 cP, about 1000 cP to about3000 cP, about 2000 cP to about 8,000 cP, about 4,000 cP to about 50,000cP, about 10,000 cP to about 500,000 cP, about 15,000 cP to about1,000,000 cP. In other embodiments, when an even more viscous medium isdesired, the biocompatible gel comprises at least about 35%, at leastabout 45%, at least about 55%, at least about 65%, at least about 70%,at least about 75%, or even at least about 80% or so by weight of thefree-radical modulating agent. In highly concentrated samples, thebiocompatible enhanced viscosity formulation comprises at least about25%, at least about 35%, at least about 45%, at least about 55%, atleast about 65%, at least about 75%, at least about 85%, at least about90% or at least about 95% or more by weight of the free-radicalmodulating agent.

In some embodiments, the viscosity of the gel formulations presentedherein are measured by any means described. For example, in someembodiments, an LVDV-II+CP Cone Plate Viscometer and a Cone SpindleCPE-40 is used to calculate the viscosity of the gel formulationdescribed herein. In other embodiments, a Brookfield (spindle and cup)viscometer is used to calculate the viscosity of the gel formulationdescribed herein. In some embodiments, the viscosity ranges referred toherein are measured at room temperature. In other embodiments, theviscosity ranges referred to herein are measured at body temperature(e.g., at the average body temperature of a healthy human).

In one embodiment, the pharmaceutically acceptable enhanced viscosityauris-acceptable formulation comprises at least one free-radicalmodulating agent and at least one gelling agent. Suitable gelling agentsfor use in preparation of the gel formulation include, but are notlimited to, celluloses, cellulose derivatives, cellulose ethers (e.g.,carboxymethylcellulose, ethylcellulose, hydroxyethylcellulose,hydroxymethylcellulose, hydroxypropylmethylcellulose,hydroxypropylcellulose, methylcellulose), guar gum, xanthan gum, locustbean gum, alginates (e.g., alginic acid), silicates, starch, tragacanth,carboxyvinyl polymers, carrageenan, paraffin, petrolatum and anycombinations or mixtures thereof. In some other embodiments,hydroxypropylmethylcellulose (Methocel®) is utilized as the gellingagent. In certain embodiments, the viscosity enhancing agents describedherein are also utilized as the gelling agent for the gel formulationspresented herein.

In some embodiments, the otic therapeutic agents disclosed herein aredispensed as an auris-acceptable paint. As used herein, paints (alsoknown as film formers) are solutions comprised of a solvent, a monomeror polymer, an active agent, and optionally one or morepharmaceutically-acceptable excipients. After application to a tissue,the solvent evaporates leaving behind a thin coating comprised of themonomers or polymers, and the active agent. The coating protects activeagents and maintains them in an immobilized state at the site ofapplication. This decreases the amount of active agent which may be lostand correspondingly increases the amount delivered to the subject. Byway of non-limiting example, paints include collodions (e.g., FlexibleCollodion, USP), and solutions comprising saccharide siloxane copolymersand a cross-linking agent. Collodions are ethyl ether/ethanol solutionscontaining pyroxylin (a nitrocellulose). After application, the ethylether/ethanol solution evaporates leaving behind a thin film ofpyroxylin. In solutions comprising saccharide siloxane copolymers, thesaccharide siloxane copolymers form the coating after evaporation of thesolvent initiates the cross-linking of the saccharide siloxanecopolymers. For additional disclosures regarding paints, see Remington:The Science and Practice of Pharmacy which is hereby incorporated withrespect to this subject matter. The paints contemplated for use herein,are flexible such that they do not interfere with the propagation ofpressure waves through the ear. Further, the paints may be applied as aliquid (i.e., solution, suspension, or emulsion), a semisolid (i.e., agel, foam, paste, or jelly) or an aerosol.

In some embodiments, the otic therapeutic agents disclosed herein aredispensed as a controlled-release foam. Examples of suitable foamablecarriers for use in the compositions disclosed herein include, but arenot limited to, alginate and derivatives thereof, carboxymethylcelluloseand derivatives thereof, collagen, polysaccharides, including, forexample, dextran, dextran derivatives, pectin, starch, modified starchessuch as starches having additional carboxyl and/or carboxamide groupsand/or having hydrophilic side-chains, cellulose and derivativesthereof, agar and derivatives thereof, such as agar stabilised withpolyacrylamide, polyethylene oxides, glycol methacrylates, gelatin, gumssuch as xanthum, guar, karaya, gellan, arabic, tragacanth and locustbean gum, or combinations thereof. Also suitable are the salts of theaforementioned carriers, for example, sodium alginate. The formulationoptionally further comprises a foaming agent, which promotes theformation of the foam, including a surfactant or external propellant.Examples of suitable foaming agents include cetrimide, lecithin, soaps,silicones and the like. Commercially available surfactants such asTween® are also suitable.

In some embodiments, other gel formulations are useful depending uponthe particular free-radical modulating agent, other pharmaceutical agentor excipients/additives used, and as such are considered to fall withinthe scope of the present disclosure. For example, othercommercially-available glycerin-based gels, glycerin-derived compounds,conjugated, or crosslinked gels, matrices, hydrogels, and polymers, aswell as gelatins and their derivatives, alginates, and alginate-basedgels, and even various native and synthetic hydrogel andhydrogel-derived compounds are all expected to be useful in thefree-radical modulating agent formulations described herein. In someembodiments, auris-acceptable gels include, but are not limited to,alginate hydrogels SAF®-Gel (ConvaTec, Princeton, N.J.), Duoderm®Hydroactive Gel (ConvaTec), Nu-gel® (Johnson & Johnson Medical,Arlington, Tex.); Carrasyn® (V) Acemannan Hydrogel (CarringtonLaboratories, Inc., Irving, Tex.); glycerin gels Elta® Hydrogel(Swiss-American Products, Inc., Dallas, Tex.) and K-Y® Sterile (Johnson& Johnson). In further embodiments, biodegradable biocompatible gelsalso represent compounds present in auris-acceptable formulationsdisclosed and described herein.

In some formulations developed for administration to a mammal, and forcompositions formulated for human administration, the auris-acceptablegel comprises substantially all of the weight of the composition. Inother embodiments, the auris-acceptable gel comprises as much as about98% or about 99% of the composition by weight. This is desirous when asubstantially non-fluid, or substantially viscous formulation is needed.In a further embodiment, when slightly less viscous, or slightly morefluid auris-acceptable pharmaceutical gel formulations are desired, thebiocompatible gel portion of the formulation comprises at least about50% by weight, at least about 60% by weight, at least about 70% byweight, or even at least about 80% or 90% by weight of the compound. Allintermediate integers within these ranges are contemplated to fallwithin the scope of this disclosure, and in some alternativeembodiments, even more fluid (and consequently less viscous)auris-acceptable gel compositions are formulated, such as for example,those in which the gel or matrix component of the mixture comprises notmore than about 50% by weight, not more than about 40% by weight, notmore than about 30% by weight, or even those than comprise not more thanabout 15% or about 20% by weight of the composition.

Auris-Acceptable Suspending Agents

In one embodiment, at least one free-radical modulating agent isincluded in a pharmaceutically acceptable enhanced viscosity formulationwherein the formulation further comprises at least one suspending agent,wherein the suspending agent assists in imparting controlled releasecharacteristics to the formulation. In some embodiments, suspendingagents also serve to increase the viscosity of the auris-acceptablefree-radical modulating agent formulations and compositions.

Suspending agents include, by way of example only, compounds such aspolyvinylpyrrolidone, e.g., polyvinylpyrrolidone K12,polyvinylpyrrolidone K17, polyvinylpyrrolidone K25, orpolyvinylpyrrolidone K30, vinyl pyrrolidone/vinyl acetate copolymer(S630), sodium carboxymethylcellulose, methylcellulose,hydroxypropylmethylcellulose (hypromellose), hydroxymethylcelluloseacetate stearate, polysorbate-80, hydroxyethylcellulose, sodiumalginate, gums, such as, e.g., gum tragacanth and gum acacia, guar gum,xanthans, including xanthan gum, sugars, cellulosics, such as, e.g.,sodium carboxymethylcellulose, methylcellulose, sodiumcarboxymethylcellulose, hydroxypropylmethylcellulose,hydroxyethylcellulose, polysorbate-80, sodium alginate, polyethoxylatedsorbitan monolaurate, polyethoxylated sorbitan monolaurate, povidone andthe like. In some embodiments, useful aqueous suspensions also containone or more polymers as suspending agents. Useful polymers includewater-soluble polymers such as cellulosic polymers, e.g., hydroxypropylmethylcellulose, and water-insoluble polymers such as cross-linkedcarboxyl-containing polymers.

In one embodiment, the present disclosure provides auris-acceptable gelcompositions comprising a therapeutically effective amount of afree-radical modulator in a hydroxyethyl cellulose gel. Hydroxyethylcellulose (HEC) is obtained as a dry powder which is reconstituted inwater or an aqueous buffer solution to give the desired viscosity(generally about 200 cps to about 30,000 cps, corresponding to about 0.2to about 10% HEC). In one embodiment the concentration of HEC is betweenabout 1% and about 15%, about 1% and about 2%, or about 1.5% to about2%.

In other embodiments, the auris-acceptable formulations, including gelformulations and viscosity-enhanced formulations, further includeexcipients, other medicinal or pharmaceutical agents, carriers,adjuvants, such as preserving, stabilizing, wetting or emulsifyingagents, solution promoters, salts, solubilizers, an antifoaming agent,an antioxidant, a dispersing agent, a wetting agent, a surfactant, andcombinations thereof.

Auris-Acceptable Actinic Radiation Curable Gel

In other embodiments, the gel is an actinic radiation curable gel, suchthat following administration to or near the targeted auris structure,use of actinic radiation (or light, including UV light, visible light,or infrared light) the desired gel properties are formed. By way ofexample only, fiber optics are used to provide the actinic radiation soas to form the desired gel properties. In some embodiments, the fiberoptics and the gel administration device form a single unit. In otherembodiments, the fiber optics and the gel administration device areprovided separately.

Auris-Acceptable Solvent Release Gel

In some embodiments, the gel is a solvent release gel such that thedesired gel properties are formed after administration to or near thetargeted auris structure, that is, as the solvent in the injected gelformulation diffuses out the gel, a gel having the desired gelproperties is formed. For example, a formulation that comprises sucroseacetate isobutyrate, a pharmaceutically acceptable solvent, one or moreadditives, and the free-radical modulating agent is administered at ornear the round window membrane: diffusion of the solvent out of theinjected formulation provides a depot having the desired gel properties.For example, use of a water soluble solvent provides a high viscositydepot when the solvent diffuses rapidly out of the injected formulation.On the other hand, use of a hydrophobic solvent (e.g., benzyl benzoate)provides a less viscous depot. One example of an auris-acceptablesolvent release gel formulation is the SABER™ Delivery System marketedby DURECT Corporation.

Auris-Acceptable In Situ Forming Spongy Material

Also contemplated within the scope of the embodiments is the use of aspongy material, formed in situ in the auris interna or auris media. Insome embodiments, the spongy material is formed from hyaluronic acid orits derivatives. The spongy material is impregnated with a desiredfree-radical modulating agent and placed within the auris media so as toprovide controlled release of the free-radical modulating agent withinthe auris media, or in contact with the round window membrane so as toprovide controlled release of the free-radical modulating agent into theauris interna. In some embodiments, the spongy material isbiodegradable.

Round Window Membrane Mucoadhesives

Also contemplated within the scope of the embodiments is the addition ofa round window membrane mucoadhesive with the free-radical modulatingagent formulations and compositions and devices disclosed herein. Theterm ‘mucoadhesion’ is used for materials that bind to the mucin layerof a biological membrane, such as the external membrane of the 3-layeredround window membrane. To serve as round window membrane mucoadhesivepolymers, the polymers possess some general physiochemical features suchas predominantly anionic hydrophilicity with numerous hydrogen bondforming groups, suitable surface property for wetting mucus/mucosaltissue surfaces or sufficient flexibility to penetrate the mucusnetwork.

Round window membrane mucoadhesive agents that are used with theauris-acceptable formulations include, but are not limited to, at leastone soluble polyvinylpyrrolidone polymer (PVP); a water-swellable, butwater-insoluble, fibrous, cross-linked carboxy-functional polymer; acrosslinked poly(acrylic acid) (e.g., Carbopol® 947P); a carbomerhomopolymer; a carbomer copolymer; a hydrophilic polysaccharide gum,maltodextrin, a cross-linked alignate gum gel, a water-dispersiblepolycarboxylated vinyl polymer, at least two particulate componentsselected from the group consisting of titanium dioxide, silicon dioxide,and clay, or a mixture thereof. The round window membrane mucoadhesiveagent is optionally used in combination with an auris-acceptableviscosity increasing excipient, or used alone to increase theinteraction of the composition with the mucosal layer target oticcomponent. In one non-limiting example, the mucoadhesive agent ismaltodextrin. In some embodiments, the mucoadhesive agent is an alginategum. When used, the round window membrane mucoadhesive characterimparted to the composition is at a level that is sufficient to deliveran effective amount of the free-radical modulating agent composition to,for example, the mucosal layer of round window membrane or the cristafenestrae cochleae in an amount that coats the mucosal membrane, andthereafter deliver the composition to the affected areas, including byway of example only, the vestibular and/or cochlear structures of theauris interna. When used, the mucoadhesive characteristics of thecompositions provided herein are determined, and using this information(along with the other teachings provided herein), the appropriateamounts are determined. One method for determining sufficientmucoadhesiveness includes monitoring changes in the interaction of thecomposition with a mucosal layer, including but not limited to measuringchanges in residence or retention time of the composition in the absenceand presence of the mucoadhesive excipient.

Mucoadhesive agents have been described, for example, in U.S. Pat. Nos.6,638,521, 6,562,363, 6,509,028, 6,348,502, 6,319,513, 6,306,789,5,814,330, and 4,900,552, each of which is hereby incorporated byreference for such disclosure.

In another non-limiting example, a mucoadhesive agent is, for example,at least two particulate components selected from titanium dioxide,silicon dioxide, and clay, wherein the composition is not furtherdiluted with any liquid prior to administration and the level of silicondioxide, if present, is from about 3% to about 15%, by weight of thecomposition. Silicon dioxide, if present, includes fumed silicondioxide, precipitated silicon dioxide, coacervated silicon dioxide, gelsilicon dioxide, and mixtures thereof. Clay, if present, includes kaolinminerals, serpentine minerals, smectites, illite or a mixture thereof.For example, clay includes laponite, bentonite, hectorite, saponite,montmorillonites or a mixture thereof.

In one non-limiting example, the round window membrane mucoadhesiveagent is maltodextrin. Maltodextrin is a carbohydrate produced by thehydrolysis of starch that is optionally derived from corn, potato, wheator other plant products. Maltodextrin is optionally used either alone orin combination with other round window membrane mucoadhesive agents toimpart mucoadhesive characteristics on the compositions disclosedherein. In one embodiment, a combination of maltodextrin and a carbopolpolymer are used to increase the round window membrane mucoadhesivecharacteristics of the compositions or devices disclosed herein.

In another embodiment, the round window membrane mucoadhesive agent isan alkyl-glycoside and/or a saccharide alkyl ester. As used herein, an“alkyl-glycoside” means a compound comprising any hydrophilic saccharide(e.g., sucrose, maltose, or glucose) linked to a hydrophobic alkyl. Insome embodiments, the round window membrane mucoadhesive agent is analkyl-glycoside wherein the alkyl-glycoside comprises a sugar linked toa hydrophobic alkyl (e.g., an alkyl comprising about 6 to about 25carbon atoms) by an amide linkage, an amine linkage, a carbamatelinkage, an ether linkage, a thioether linkage, an ester linkage, athioester linkage, a glycosidic linkage, a thioglycosidic linkage,and/or a ureide linkage. In some embodiments, the round window membranemucoadhesive agent is a hexyl-, heptyl-, octyl-, nonyl-, decyl-,undecyl-, dodecyl-, tridecyl-, tetradecyl, pentadecyl-, hexadecyl-,heptadecyl-, and octadecyl α- or β-D-maltoside; hexyl-, heptyl-, octyl-,nonyl-, decyl-, undecyl-, dodecyl-, tridecyl-, tetradecyl, pentadecyl-,hexadecyl-, heptadecyl-, and octadecyl α- or β-D-glucoside; hexyl-,heptyl-, octyl-, nonyl-, decyl-, undecyl-, dodecyl-, tridecyl-,tetradecyl, pentadecyl-, hexadecyl-, heptadecyl-, and octadecyl α- orβ-D-sucroside; hexyl-, heptyl-, octyl-, dodecyl-, tridecyl-, andtetradecyl-β-D-thiomaltoside; dodecyl maltoside; heptyl- oroctyl-1-thio-α- or β-D-glucopyranoside; alkyl thiosucroses; alkylmaltotriosides; long chain aliphatic carbonic acid amides of sucroseβ-amino-alkyl ethers; derivatives of palatinose or isomaltamine linkedby an amide linkage to an alkyl chain and derivatives of isomaltaminelinked by urea to an alkyl chain; long chain aliphatic carbonic acidureides of sucrose β-amino-alkyl ethers and long chain aliphaticcarbonic acid amides of sucrose β-amino-alkyl ethers. In someembodiments, the round window membrane mucoadhesive agent is analkyl-glycoside wherein the alkyl glycoside is maltose, sucrose,glucose, or a combination thereof linked by a glycosidic linkage to analkyl chain of 9-16 carbon atoms (e.g., nonyl-, decyl-, dodecyl- andtetradecyl sucroside; nonyl-, decyl-, dodecyl- and tetradecyl glucoside;and nonyl-, decyl-, dodecyl- and tetradecyl maltoside). In someembodiments, the round window membrane mucoadhesive agent is analkyl-glycoside wherein the alkyl glycoside is dodecylmaltoside,tridecylmaltoside, and tetradecylmaltoside.

In some embodiments, the round window membrane mucoadhesive agent is analkyl-glycoside wherein the alkyl-glycoside is a disaccharide with atleast one glucose. In some embodiments, the auris acceptable penetrationenhancer is a surfactant comprisingα-D-glucopyranosyl-β-glycopyranoside,n-Dodecyl-4-O-α-D-glucopyranosyl-β-glycopyranoside, and/orn-tetradecyl-4-O-α-D-glucopyranosyl-β-glycopyranoside. In someembodiments, the round window membrane mucoadhesive agent is analkyl-glycoside wherein the alkyl-glycoside has a critical miscelleconcentration (CMC) of less than about 1 mM in pure water or in aqueoussolutions. In some embodiments, the round window membrane mucoadhesiveagent is an alkyl-glycoside wherein an oxygen atom within thealkyl-glycoside is substituted with a sulfur atom. In some embodiments,the round window membrane mucoadhesive agent is an alkyl-glycosidewherein the alkylglycoside is the β anomer. In some embodiments, theround window membrane mucoadhesive agent is an alkyl-glycoside whereinthe alkylglycoside comprises 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98%, 99%, 99.1%, 99.5%, or 99.9% of the β anomer.

Auris-Acceptable Controlled Release Particles

Free-radical modulating agents and/or other pharmaceutical agentsdisclosed herein are optionally incorporated within controlled releaseparticles, lipid complexes, liposomes, nanoparticles, microparticles,microspheres, coacervates, nanocapsules or other agents which enhance orfacilitate the localized delivery of the free-radical modulating agent.In some embodiments, a single enhanced viscosity formulation is used, inwhich at least one free-radical modulating agent is present, while inother embodiments, a pharmaceutical formulation that comprises a mixtureof two or more distinct enhanced viscosity formulations is used, inwhich at least one free-radical modulating agent is present. In someembodiments, combinations of sols, gels and/or biocompatible matrices isalso employed to provide desirable characteristics of the controlledrelease free-radical modulating agent compositions or formulations. Incertain embodiments, the controlled release free-radical modulatingagent formulations or compositions are cross-linked by one or moreagents to alter or improve the properties of the composition.

Examples of microspheres relevant to the pharmaceutical formulationsdisclosed herein include: Luzzi, L. A., J. Pharm. Psy. 59:1367 (1970);U.S. Pat. No. 4,530,840; Lewis, D. H., “Controlled Release of BioactiveAgents from Lactides/Glycolide Polymers” in Biodegradable Polymers asDrug Delivery Systems, Chasin, M. and Langer, R., eds., Marcel Decker(1990); U.S. Pat. No. 4,675,189; Beck et al., “Poly(lactic acid) andPoly(lactic acid-co-glycolic acid) Contraceptive Delivery Systems,” inLong Acting Steroid Contraception, Mishell, D. R., ed., Raven Press(1983); U.S. Pat. No. 4,758,435; U.S. Pat. No. 3,773,919; U.S. Pat. No.4,474,572. Examples of protein therapeutics formulated as microspheresinclude: U.S. Pat. No. 6,458,387; U.S. Pat. No. 6,268,053; U.S. Pat. No.6,090,925; U.S. Pat. No. 5,981,719; and U.S. Pat. No. 5,578,709, and areherein incorporated by reference for such disclosure.

Microspheres usually have a spherical shape, although irregularly-shapedmicroparticles are possible. Microspheres may vary in size, ranging fromsubmicron to 1000 micron diameters. Microspheres suitable for use withthe auris-acceptable formulations disclosed herein are submicron to 250micron diameter microspheres, allowing administration by injection witha standard gauge needle. The auris-acceptable microspheres are preparedby any method which produces microspheres in a size range acceptable foruse in an injectable composition. Injection is optionally accomplishedwith standard gauge needles used for administering liquid compositions.

Suitable examples of polymeric matrix materials for use in theauris-acceptable controlled release particles herein includepoly(glycolic acid), poly-d,l-lactic acid, poly-1-lactic acid,copolymers of the foregoing, poly(aliphatic carboxylic acids),copolyoxalates, polycaprolactone, polydioxonene, poly(orthocarbonates),poly(acetals), poly(lactic acid-caprolactone), polyorthoesters,poly(glycolic acid-caprolactone), polydioxonene, polyanhydrides,polyphosphazines, and natural polymers including albumin, casein, andsome waxes, such as, glycerol mono- and distearate, and the like.Various commercially available poly(lactide-co-glycolide) materials(PLGA) are optionally used in the method disclosed herein. For example,poly(d,l-lactic-co-glycolic acid) is commercially available fromBoehringer-Ingelheim as RESOMER RG 503H. This product has a mole percentcomposition of 50% lactide and 50% glycolide. These copolymers areavailable in a wide range of molecular weights and ratios of lactic acidto glycolic acid. One embodiment includes the use of the polymerpoly(d,l-lactide-co-glycolide). The molar ratio of lactide to glycolidein such a copolymer includes the range of from about 95:5 to about50:50.

The molecular weight of the polymeric matrix material is of someimportance. The molecular weight should be high enough so that it formssatisfactory polymer coatings, i.e., the polymer should be a good filmformer. Usually, a satisfactory molecular weight is in the range of5,000 to 500,000 daltons. The molecular weight of a polymer is alsoimportant from the point of view that molecular weight influences thebiodegradation rate of the polymer. For a diffusional mechanism of drugrelease, the polymer should remain intact until all of the drug isreleased from the microparticles and then degrade. The drug is alsoreleased from the microparticles as the polymeric excipient bioerodes.By an appropriate selection of polymeric materials a microsphereformulation is made such that the resulting microspheres exhibit bothdiffusional release and biodegradation release properties. This isuseful in affording multiphasic release patterns.

A variety of methods are known by which compounds are encapsulated inmicrospheres. In these methods, the free-radical modulating agent isgenerally dispersed or emulsified, using stirrers, agitators, or otherdynamic mixing techniques, in a solvent containing a wall-formingmaterial. Solvent is then removed from the microspheres, and thereafterthe microsphere product is obtained.

In one embodiment, controlled release free-radical modulating agentformulations are made through the incorporation of the free-radicalmodulating agents and/or other pharmaceutical agents into ethylene-vinylacetate copolymer matrices. (See U.S. Pat. No. 6,083,534, incorporatedherein for such disclosure). In another embodiment, free-radicalmodulating agents are incorporated into poly(lactic-glycolic acid) orpoly-L-lactic acid microspheres. Id. In yet another embodiment, thefree-radical modulating agents are encapsulated into alginatemicrospheres. (See U.S. Pat. No. 6,036,978, incorporated herein for suchdisclosure). Biocompatible methacrylate-based polymers to encapsulatethe free-radical modulating agent compounds or compositions areoptionally used in the formulations and methods disclosed herein. A widerange of methacrylate-based polymer systems are commercially available,such as the EUDRAGIT polymers marketed by Evonik. One useful aspect ofmethacrylate polymers is that the properties of the formulation arevaried by incorporating various co-polymers. For example, poly(acrylicacid-co-methylmethacrylate) microparticles exhibit enhanced mucoadhesionproperties as the carboxylic acid groups in the poly(acrylic acid) formhydrogen bonds with mucin (Park et al, Pharm. Res. (1987) 4(6):457-464).Variation of the ratio between acrylic acid and methylmethacrylatemonomers serves to modulate the properties of the co-polymer.Methacrylate-based microparticles have also been used in proteintherapeutic formulations (Naha et al, Journal of Microencapsulation Feb.4, 2008 (online publication)). In one embodiment, the enhanced viscosityauris-acceptable formulations described herein comprises free-radicalmodulating agent microspheres wherein the microspheres are formed from amethacrylate polymer or copolymer. In an additional embodiment, theenhanced viscosity formulation described herein comprises free-radicalmodulating agent microspheres wherein the microspheres are mucoadhesive.Other controlled release systems, including incorporation or deposit ofpolymeric materials or matrices onto solid or hollow spheres containingfree-radical modulating agents, are also explicitly contemplated withinthe embodiments disclosed herein. The types of controlled releasesystems available without significantly losing activity of thefree-radical modulating agent are determined using the teachings,examples, and principles disclosed herein

An example of a conventional microencapsulation process forpharmaceutical preparations is shown in U.S. Pat. No. 3,737,337,incorporated herein by reference for such disclosure. The free-radicalmodulating agent substances to be encapsulated or embedded are dissolvedor dispersed in the organic solution of the polymer (phase A), usingconventional mixers, including (in the preparation of dispersion)vibrators and high-speed stirrers, etc. The dispersion of phase (A),containing the core material in solution or in suspension, is carriedout in the aqueous phase (B), again using conventional mixers, such ashigh-speed mixers, vibration mixers, or even spray nozzles, in whichcase the particle size of the microspheres will be determined not onlyby the concentration of phase (A), but also by the emulsate ormicrosphere size. With conventional techniques for themicroencapsulation of free-radical modulating agents, the microspheresform when the solvent containing an active agent and a polymer isemulsified or dispersed in an immiscible solution by stirring,agitating, vibrating, or some other dynamic mixing technique, often fora relatively long period of time.

Methods for the construction of microspheres are also described in U.S.Pat. No. 4,389,330, and U.S. Pat. No. 4,530,840, incorporated herein byreference for such disclosure. The desired free-radical modulating agentis dissolved or dispersed in an appropriate solvent. To theagent-containing medium is added the polymeric matrix material in anamount relative to the active ingredient which gives a product of thedesired loading of active agent. Optionally, all of the ingredients ofthe free-radical modulating agent microsphere product can be blended inthe solvent medium together. Suitable solvents for the agent and thepolymeric matrix material include organic solvents such as acetone,halogenated hydrocarbons such as chloroform, methylene chloride and thelike, aromatic hydrocarbon compounds, halogenated aromatic hydrocarboncompounds, cyclic ethers, alcohols, ethyl acetate and the like.

The mixture of ingredients in the solvent is emulsified in acontinuous-phase processing medium; the continuous-phase medium beingsuch that a dispersion of microdroplets containing the indicatedingredients is formed in the continuous-phase medium. Naturally, thecontinuous-phase processing medium and the organic solvent must beimmiscible, and includes water although nonaqueous media such as xyleneand toluene and synthetic oils and natural oils are optionally used.Optionally, a surfactant is added to the continuous-phase processingmedium to prevent the microparticles from agglomerating and to controlthe size of the solvent microdroplets in the emulsion. A preferredsurfactant-dispersing medium combination is a 1 to 10 wt. % poly(vinylalcohol) in water mixture. The dispersion is formed by mechanicalagitation of the mixed materials. An emulsion is optionally formed byadding small drops of the active agent-wall forming material solution tothe continuous phase processing medium. The temperature during theformation of the emulsion is not especially critical but influences thesize and quality of the microspheres and the solubility of the drug inthe continuous phase. It is desirable to have as little of the agent inthe continuous phase as possible. Moreover, depending on the solvent andcontinuous-phase processing medium employed, the temperature must not betoo low or the solvent and processing medium will solidify or theprocessing medium will become too viscous for practical purposes, or toohigh that the processing medium will evaporate, or that the liquidprocessing medium will not be maintained. Moreover, the temperature ofthe medium cannot be so high that the stability of the particular agentbeing incorporated in the microspheres is adversely affected.Accordingly, the dispersion process is conducted at any temperaturewhich maintains stable operating conditions, which preferred temperaturebeing about 15° C. to 60° C., depending upon the drug and excipientselected.

The dispersion which is formed is a stable emulsion and from thisdispersion the organic solvent immiscible fluid is optionally partiallyremoved in the first step of the solvent removal process. The solvent isremoved by techniques such as heating, the application of a reducedpressure or a combination of both. The temperature employed to evaporatesolvent from the microdroplets is not critical, but should not be thathigh that it degrades the free-radical modulating agent employed in thepreparation of a given microparticle, nor should it be so high as toevaporate solvent at such a rapid rate to cause defects in the wallforming material. Generally, from 5 to 75%, of the solvent is removed inthe first solvent removal step.

After the first stage, the dispersed microparticles in the solventimmiscible fluid medium are isolated from the fluid medium by anyconvenient means of separation. Thus, for example, the fluid is decantedfrom the microsphere or the microsphere suspension is filtered. Stillother, various combinations of separation techniques are used ifdesired.

Following the isolation of the microspheres from the continuous-phaseprocessing medium, the remainder of the solvent in the microspheres isremoved by extraction. In this step, the microspheres are suspended inthe same continuous-phase processing medium used in step one, with orwithout surfactant, or in another liquid. The extraction medium removesthe solvent from the microspheres and yet does not dissolve themicrospheres. During the extraction, the extraction medium withdissolved solvent is optionally removed and replaced with freshextraction medium. This is best done on a continual basis. The rate ofextraction medium replenishment of a given process is a variable whichis determined at the time the process is performed and, therefore, noprecise limits for the rate must be predetermined. After the majority ofthe solvent has been removed from the microspheres, the microspheres aredried by exposure to air or by other conventional drying techniques suchas vacuum drying, drying over a desiccant, or the like. This process isvery efficient in encapsulating the free-radical modulating agent sincecore loadings of up to 80 wt. %, preferably up to 60 wt. % are obtained.

Alternatively, controlled release microspheres containing a free-radicalmodulator is prepared through the use of static mixers. Static ormotionless mixers consist of a conduit or tube in which is received anumber of static mixing agents. Static mixers provide homogeneous mixingin a relatively short length of conduit, and in a relatively shortperiod of time. With static mixers, the fluid moves through the mixer,rather than some part of the mixer, such as a blade, moving through thefluid.

A static mixer is optionally used to create an emulsion. When using astatic mixer to form an emulsion, several factors determine emulsionparticle size, including the density and viscosity of the varioussolutions or phases to be mixed, volume ratio of the phases, interfacialtension between the phases, static mixer parameters (conduit diameter;length of mixing element; number of mixing elements), and linearvelocity through the static mixer. Temperature is a variable because itaffects density, viscosity, and interfacial tension. The controllingvariables are linear velocity, sheer rate, and pressure drop per unitlength of static mixer.

In order to create microspheres containing a free-radical modulatorusing a static mixer process, an organic phase and an aqueous phase arecombined. The organic and aqueous phases are largely or substantiallyimmiscible, with the aqueous phase constituting the continuous phase ofthe emulsion. The organic phase includes a free-radical modulator aswell as a wall-forming polymer or polymeric matrix material. The organicphase is prepared by dissolving a free-radical modulator in an organicor other suitable solvent, or by forming a dispersion or an emulsioncontaining the free-radical modulating agent. The organic phase and theaqueous phase are pumped so that the two phases flow simultaneouslythrough a static mixer, thereby forming an emulsion which comprisesmicrospheres containing the free-radical modulating agent encapsulatedin the polymeric matrix material. The organic and aqueous phases arepumped through the static mixer into a large volume of quench liquid toextract or remove the organic solvent. Organic solvent is optionallyremoved from the microspheres while they are washing or being stirred inthe quench liquid. After the microspheres are washed in a quench liquid,they are isolated, as through a sieve, and dried.

In one embodiment, microspheres are prepared using a static mixer. Theprocess is not limited to the solvent extraction technique discussedabove, but is used with other encapsulation techniques. For example, theprocess is optionally used with a phase separation encapsulationtechnique. To do so, an organic phase is prepared that comprises afree-radical modulator suspended or dispersed in a polymer solution. Thenon-solvent second phase is free from solvents for the polymer andactive agent. A preferred non-solvent second phase is silicone oil. Theorganic phase and the non-solvent phase are pumped through a staticmixer into a non-solvent quench liquid, such as heptane. The semi-solidparticles are quenched for complete hardening and washing. The processof microencapsulation includes spray drying, solvent evaporation, acombination of evaporation and extraction, and melt extrusion.

In another embodiment, the microencapsulation process involves the useof a static mixer with a single solvent. This process is described indetail in U.S. application Ser. No. 08/338,805, herein incorporated byreference for such disclosure. An alternative process involves the useof a static mixer with co-solvents. In this process, biodegradablemicrospheres comprising a biodegradable polymeric binder and afree-radical modulator are prepared, which comprises a blend of at leasttwo substantially non-toxic solvents, free of halogenated hydrocarbonsto dissolve both the agent and the polymer. The solvent blend containingthe dissolved agent and polymer is dispersed in an aqueous solution toform droplets. The resulting emulsion is then added to an aqueousextraction medium preferably containing at least one of the solvents ofthe blend, whereby the rate of extraction of each solvent is controlled,whereupon the biodegradable microspheres containing the pharmaceuticallyactive agent are formed. This process has the advantage that lessextraction medium is required because the solubility of one solvent inwater is substantially independent of the other and solvent selection isincreased, especially with solvents that are particularly difficult toextract.

Nanoparticles are also contemplated for use with the free-radicalmodulating agents disclosed herein. Nanoparticles are materialstructures of about 100 nm or less in size. One use of nanoparticles inpharmaceutical formulations is the formation of suspensions as theinteraction of the particle surface with solvent is strong enough toovercome differences in density. Nanoparticle suspensions are sterilizedas the nanoparticles are small enough to be subjected to sterilizingfiltration (see, e.g., U.S. Pat. No. 6,139,870, herein incorporated byreference for such disclosure). Nanoparticles comprise at least onehydrophobic, water-insoluble and water-indispersible polymer orcopolymer emulsified in a solution or aqueous dispersion of surfactants,phospholipids or fatty acids. The free-radical modulating agent isoptionally introduced with the polymer or the copolymer into thenanoparticles.

Lipid nanocapsules as controlled release structures, as well forpenetrating the round window membrane and reaching auris interna and/orauris media targets, is also contemplated herein. Lipid nanocapsules areoptionally formed by emulsifying capric and caprylic acid triglycerides(Labrafac WL 1349; avg. mw 512), soybean lecithin (LIPOID® S75-3; 69%phosphatidylcholine and other phospholipids), surfactant (for example,Solutol HS15), a mixture of polyethylene glycol 660 hydroxystearate andfree polyethylene glycol 660; NaCl and water. The mixture is stirred atroom temperature to obtain an oil emulsion in water. After progressiveheating at a rate of 4° C./min under magnetic stirring, a short intervalof transparency should occur close to 70° C., and the inverted phase(water droplets in oil) obtained at 85° C. Three cycles of cooling andheating is then applied between 85° C. and 60° C. at the rate of 4°C./min, and a fast dilution in cold water at a temperature close to 0°C. to produce a suspension of nanocapsules. To encapsulate thefree-radical modulating agents, the agent is optionally added just priorto the dilution with cold water.

Free-radical modulating agents are also inserted into the lipidnanocapsules by incubation for 90 minutes with an aqueous micellarsolution of the auris active agent. The suspension is then vortexedevery 15 minutes, and then quenched in an ice bath for 1 minute.

Suitable auris-acceptable surfactants are, by way of example, cholicacid or taurocholic acid salts. Taurocholic acid, the conjugate formedfrom cholic acid and taurine, is a fully metabolizable sulfonic acidsurfactant. An analog of taurocholic acid, tauroursodeoxycholic acid(TUDCA), is a naturally occurring bile acid and is a conjugate oftaurine and ursodeoxycholic acid (UDCA). Other naturally occurringanionic (e.g., galactocerebroside sulfate), neutral (e.g.,lactosylceramide) or zwitterionic surfactants (e.g., sphingomyelin,phosphatidyl choline, palmitoyl carnitine) are optionally used toprepare nanoparticles.

The auris-acceptable phospholipids are chosen, by way of example, fromnatural, synthetic or semi-synthetic phospholipids; lecithins(phosphatidylcholine) such as, for example, purified egg or soyalecithins (lecithin E100, lecithin E80 and phospholipons, for examplephospholipon 90), phosphatidylethanolamine, phosphatidylserine,phosphatidylinositol, phosphatidylglycerol,dipalmitoylphosphatidylcholine, dipalmitoylglycerophosphatidylcholine,dimyristoylphosphatidylcholine, distearoylphosphatidylcholine andphosphatidic acid or mixtures thereof are used more particularly.

Fatty acids for use with the auris-acceptable formulations are chosenfrom, by way of example, lauric acid, mysristic acid, palmitic acid,stearic acid, isostearic acid, arachidic acid, behenic acid, oleic acid,myristoleic acid, palmitoleic acid, linoleic acid, alpha-linoleic acid,arachidonic acid, eicosapentaenoic acid, erucic acid, docosahexaenoicacid, and the like.

Suitable auris-acceptable surfactants are selected from known organicand inorganic pharmaceutical excipients. Such excipients include variouspolymers, low molecular weight oligomers, natural products, andsurfactants. Preferred surface modifiers include nonionic and ionicsurfactants. Two or more surface modifiers are used in combination.

Representative examples of auris-acceptable surfactants include cetylpyridinium chloride, gelatin, casein, lecithin (phosphatides), dextran,glycerol, gum acacia, cholesterol, tragacanth, stearic acid, calciumstearate, glycerol monostearate, cetostearyl alcohol, cetomacrogolemulsifying wax, sorbitan esters, polyoxyethylene alkyl ethers,polyoxyethylene castor oil derivatives, polyoxyethylene sorbitan fattyacid esters; dodecyl trimethyl ammonium bromide,polyoxyethylenestearates, colloidal silicon dioxide, phosphates, sodiumdodecylsulfate, carboxymethylcellulose calcium, hydroxypropyl cellulose(HPC, HPC-SL, and HPC-L), hydroxypropyl methylcellulose (HPMC),carboxymethylcellulose sodium, methylcellulose, hydroxyethylcellulose,hydroxypropylcellulose, hydroxypropylmethyl-cellulose phthalate,noncrystalline cellulose, magnesium aluminum silicate, triethanolamine,polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP),4-(1,1,3,3-tetaamethylbutyl)-phenol polymer with ethylene oxide andformaldehyde (also known as tyloxapol, superione, and triton),poloxamers, poloxamines, a charged phospholipid such as dimyristoylphophatidyl glycerol, dioctylsulfosuccinate (DOSS); Tetronic® 1508,dialkylesters of sodium sulfosuccinic acid, Duponol P, Tritons X-200,Crodestas F-110, p-isononylphenoxypoly-(glycidol), Crodestas SL-40(Croda, Inc.); and SA90HCO, which isC₁₈H₃₇CH₂(CON(CH₃)—CH₂(CHOH)₄(CH₂OH)₂ (Eastman Kodak Co.);decanoyl-N-methylglucamide; n-decyl β-D-glucopyranoside; n-decylβ-D-maltopyranoside; n-dodecyl β-D-glucopyranoside; n-dodecylβ-D-maltoside; heptanoyl-N-methylglucamide;n-heptyl-β-D-glucopyranoside; n-heptyl β-D-thioglucoside; n-hexylβ-D-glucopyranoside; nonanoyl-N-methylglucamide; n-noylβ-D-glucopyranoside; octanoyl-N-methylglucamide;n-octyl-β-D-glucopyranoside; octyl β-D-thioglucopyranoside; and thelike. Most of these surfactants are known pharmaceutical excipients andare described in detail in the Handbook of Pharmaceutical Excipients,published jointly by the American Pharmaceutical Association and ThePharmaceutical Society of Great Britain (The Pharmaceutical Press,1986), specifically incorporated by reference for such disclosure.

The hydrophobic, water-insoluble and water-indispersible polymer orcopolymer may be chosen from biocompatible and biodegradable polymers,for example lactic or glycolic acid polymers and copolymers thereof, orpolylactic/polyethylene (or polypropylene) oxide copolymers, preferablywith molecular weights of between 1000 and 200,000, polyhydroxybutyricacid polymers, polylactones of fatty acids containing at least 12 carbonatoms, or polyanhydrides.

The nanoparticles may be obtained by coacervation, or by the techniqueof evaporation of solvent, from an aqueous dispersion or solution ofphospholipids and of an oleic acid salt into which is added animmiscible organic phase comprising the active principle and thehydrophobic, water-insoluble and water-indispersible polymer orcopolymer. The mixture is pre-emulsified and then subjected tohomogenization and evaporation of the organic solvent to obtain anaqueous suspension of very small-sized nanoparticles.

A variety of methods are optionally employed to fabricate thefree-radical modulating agent nanoparticles that are within the scope ofthe embodiments. These methods include vaporization methods, such asfree jet expansion, laser vaporization, spark erosion, electro explosionand chemical vapor deposition; physical methods involving mechanicalattrition (e.g., “pearlmilling” technology, Elan Nanosystems), supercritical CO2 and interfacial deposition following solvent displacement.In one embodiment, the solvent displacement method is used. The size ofnanoparticles produced by this method is sensitive to the concentrationof polymer in the organic solvent; the rate of mixing; and to thesurfactant employed in the process. Continuous flow mixers provide thenecessary turbulence to ensure small particle size. One type ofcontinuous flow mixing device that is optionally used to preparenanoparticles has been described (Hansen et al J Phys Chem 92, 2189-96,1988). In other embodiments, ultrasonic devices, flow throughhomogenizers or supercritical CO₂ devices may be used to preparenanoparticles.

If suitable nanoparticle homogeneity is not obtained on directsynthesis, then size-exclusion chromatography is used to produce highlyuniform drug-containing particles that are freed of other componentsinvolved in their fabrication. Size-exclusion chromatography (SEC)techniques, such as gel-filtration chromatography, is used to separateparticle-bound free-radical modulating agent or other pharmaceuticalcompound from free free-radical modulating agent or other pharmaceuticalcompound, or to select a suitable size range of free-radical modulatingagent-containing nanoparticles. Various SEC media, such as Superdex 200,Superose 6, Sephacryl 1000 are commercially available and are employedfor the size-based fractionation of such mixtures. Additionally,nanoparticles are optionally purified by centrifugation, membranefiltration and by use of other molecular sieving devices, crosslinkedgels/materials and membranes.

Auris-Acceptable Cyclodextrin and Other Stabilizing Formulations

In a specific embodiment, the auris-acceptable formulationsalternatively comprises a cyclodextrin. Cyclodextrins are cyclicoligosaccharides containing 6, 7, or 8 glucopyranose units, referred toas α-cyclodextrin, β-cyclodextrin, or γ-cyclodextrin respectively.Cyclodextrins have a hydrophilic exterior, which enhances water-soluble,and a hydrophobic interior which forms a cavity. In an aqueousenvironment, hydrophobic portions of other molecules often enter thehydrophobic cavity of cyclodextrin to form inclusion compounds.Additionally, cyclodextrins are also capable of other types ofnonbonding interactions with molecules that are not inside thehydrophobic cavity. Cyclodextrins have three free hydroxyl groups foreach glucopyranose unit, or 18 hydroxyl groups on α-cyclodextrin, 21hydroxyl groups on β-cyclodextrin, and 24 hydroxyl groups onγ-cyclodextrin. One or more of these hydroxyl groups can be reacted withany of a number of reagents to form a large variety of cyclodextrinderivatives, including hydroxypropyl ethers, sulfonates, andsulfoalkylethers. Shown below is the structure of β-cyclodextrin and thehydroxypropyl-β-cyclodextrin (HPβCD).

In some embodiments, the use of cyclodextrins in the pharmaceuticalcompositions described herein improves the solubility of the drug.Inclusion compounds are involved in many cases of enhanced solubility;however other interactions between cyclodextrins and insoluble compoundsalso improves solubility. Hydroxypropyl-β-cyclodextrin (HPβCD) iscommercially available as a pyrogen free product. It is a nonhygroscopicwhite powder that readily dissolves in water. HPβCD is thermally stableand does not degrade at neutral pH. Thus, cyclodextrins improve thesolubility of a therapeutic agent in a composition or formulation.Accordingly, in some embodiments, cyclodextrins are included to increasethe solubility of the auris-acceptable free-radical modulating agentswithin the formulations described herein. In other embodiments,cyclodextrins in addition serve as controlled release excipents withinthe formulations described herein.

By way of example only, cyclodextrin derivatives for use includeα-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, hydroxyethylβ-cyclodextrin, hydroxypropyl γ-cyclodextrin, sulfated β-cyclodextrin,sulfated α-cyclodextrin, sulfobutyl ether β-cyclodextrin.

The concentration of the cyclodextrin used in the compositions andmethods disclosed herein varies according to the physiochemicalproperties, pharmacokinetic properties, side effect or adverse events,formulation considerations, or other factors associated with thetherapeutically active agent, or a salt or prodrug thereof, or with theproperties of other excipients in the composition. Thus, in certaincircumstances, the concentration or amount of cyclodextrin used inaccordance with the compositions and methods disclosed herein will vary,depending on the need. When used, the amount of cyclodextrins needed toincrease solubility of the free-radical modulating agent and/or functionas a controlled release excipient in any of the formulations describedherein is selected using the principles, examples, and teachingsdescribed herein.

Other stabilizers that are useful in the auris-acceptable formulationsdisclosed herein include, for example, fatty acids, fatty alcohols,alcohols, long chain fatty acid esters, long chain ethers, hydrophilicderivatives of fatty acids, polyvinyl pyrrolidones, polyvinyl ethers,polyvinyl alcohols, hydrocarbons, hydrophobic polymers,moisture-absorbing polymers, and combinations thereof. In someembodiments, amide analogues of stabilizers are also used. In furtherembodiments, the chosen stabilizer changes the hydrophobicity of theformulation (e.g., oleic acid, waxes), or improves the mixing of variouscomponents in the formulation (e.g., ethanol), controls the moisturelevel in the formula (e.g., PVP or polyvinyl pyrrolidone), controls themobility of the phase (substances with melting points higher than roomtemperature such as long chain fatty acids, alcohols, esters, ethers,amides etc. or mixtures thereof; waxes), and/or improves thecompatibility of the formula with encapsulating materials (e.g., oleicacid or wax). In another embodiment some of these stabilizers are usedas solvents/co-solvents (e.g., ethanol). In other embodiments,stabilizers are present in sufficient amounts to inhibit the degradationof the free-radical modulating agent. Examples of such stabilizingagents, include, but are not limited to: (a) about 0.5% to about 2% w/vglycerol, (b) about 0.1% to about 1% w/v methionine, (c) about 0.1% toabout 2% w/v monothioglycerol, (d) about 1 mM to about 10 mM EDTA, (e)about 0.01% to about 2% w/v ascorbic acid, (f) 0.003% to about 0.02% w/vpolysorbate 80, (g) 0.001% to about 0.05% w/v. polysorbate 20, (h)arginine, (i) heparin, (j) dextran sulfate, (k) cyclodextrins, (l)pentosan polysulfate and other heparinoids, (m) divalent cations such asmagnesium and zinc; or (n) combinations thereof.

Additional useful free-radical modulating agent auris-acceptableformulations include one or more anti-aggregation additives to enhancestability of free-radical modulating agent formulations by reducing therate of protein aggregation. The anti-aggregation additive selecteddepends upon the nature of the conditions to which the free-radicalmodulating agents, for example free-radical modulating agent antibodiesare exposed. For example, certain formulations undergoing agitation andthermal stress require a different anti-aggregation additive than aformulation undergoing lyophilization and reconstitution. Usefulanti-aggregation additives include, by way of example only, urea,guanidinium chloride, simple amino acids such as glycine or arginine,sugars, polyalcohols, polysorbates, polymers such as polyethylene glycoland dextrans, alkyl saccharides, such as alkyl glycoside, andsurfactants.

Other useful formulations optionally include one or moreauris-acceptable antioxidants to enhance chemical stability whererequired. Suitable antioxidants include, by way of example only,ascorbic acid, methionine, sodium thiosulfate and sodium metabisulfite.In one embodiment, antioxidants are selected from metal chelatingagents, thiol containing compounds and other general stabilizing agents.

Still other useful compositions include one or more auris-acceptablesurfactants to enhance physical stability or for other purposes.Suitable nonionic surfactants include, but are not limited to,polyoxyethylene fatty acid glycerides and vegetable oils, e.g.,polyoxyethylene (60) hydrogenated castor oil; and polyoxyethylenealkylethers and alkylphenyl ethers, e.g., octoxynol 10, octoxynol 40.

In some embodiments, the auris-acceptable pharmaceutical formulationsdescribed herein are stable with respect to compound degradation over aperiod of any of at least about 1 day, at least about 2 days, at leastabout 3 days, at least about 4 days, at least about 5 days, at leastabout 6 days, at least about 1 week, at least about 2 weeks, at leastabout 3 weeks, at least about 4 weeks, at least about 5 weeks, at leastabout 6 weeks, at least about 7 weeks, at least about 8 weeks, at leastabout 3 months, at least about 4 months, at least about 5 months, or atleast about 6 months. In other embodiments, the formulations describedherein are stable with respect to compound degradation over a period ofat least about 1 week. Also described herein are formulations that arestable with respect to compound degradation over a period of at leastabout 1 month.

In other embodiments, an additional surfactant (co-surfactant) and/orbuffering agent is combined with one or more of the pharmaceuticallyacceptable vehicles previously described herein so that the surfactantand/or buffering agent maintains the product at an optimal pH forstability. Suitable co-surfactants include, but are not limited to: a)natural and synthetic lipophilic agents, e.g., phospholipids,cholesterol, and cholesterol fatty acid esters and derivatives thereof,b) nonionic surfactants, which include for example, polyoxyethylenefatty alcohol esters, sorbitan fatty acid esters (Spans),polyoxyethylene sorbitan fatty acid esters (e.g., polyoxyethylene (20)sorbitan monooleate (Tween 80), polyoxyethylene (20) sorbitanmonostearate (Tween 60), polyoxyethylene (20) sorbitan monolaurate(Tween 20) and other Tweens, sorbitan esters, glycerol esters, e.g.,Myrj and glycerol triacetate (triacetin), polyethylene glycols, cetylalcohol, cetostearyl alcohol, stearyl alcohol, polysorbate 80,poloxamers, poloxamines, polyoxyethylene castor oil derivatives (e.g.,Cremophor® RH40, Cremphor A25, Cremphor A20, Cremophor® EL) and otherCremophors, sulfosuccinates, alkyl sulphates (SLS); PEG glyceryl fattyacid esters such as PEG-8 glyceryl caprylate/caprate (Labrasol), PEG-4glyceryl caprylate/caprate (Labrafac Hydro WL 1219), PEG-32 glyceryllaurate (Gelucire 444/14), PEG-6 glyceryl mono oleate (Labrafil M 1944CS), PEG-6 glyceryl linoleate (Labrafil M 2125 CS); propylene glycolmono- and di-fatty acid esters, such as propylene glycol laurate,propylene glycol caprylate/caprate; Brij® 700, ascorbyl-6-palmitate,stearylamine, sodium lauryl sulfate, polyoxethyleneglyceroltriiricinoleate, and any combinations or mixtures thereof; c) anionicsurfactants include, but are not limited to, calciumcarboxymethylcellulose, sodium carboxymethylcellulose, sodiumsulfosuccinate, dioctyl, sodium alginate, alkyl polyoxyethylenesulfates, sodium lauryl sulfate, triethanolamine stearate, potassiumlaurate, bile salts, and any combinations or mixtures thereof, and d)cationic surfactants such as cetyltrimethylammonium bromide, andlauryldimethylbenzyl-ammonium chloride.

In a further embodiment, when one or more co-surfactants are utilized inthe auris-acceptable formulations of the present disclosure, they arecombined, e.g., with a pharmaceutically acceptable vehicle and ispresent in the final formulation, e.g., in an amount ranging from about0.1% to about 20%, from about 0.5% to about 10%.

In one embodiment, the surfactant has an HLB value of 0 to 20. Inadditional embodiments, the surfactant has an HLB value of 0 to 3, of 4to 6, of 7 to 9, of 8 to 18, of 13 to 15, of 10 to 18.

In one embodiment, diluents are also used to stabilize the free-radicalmodulating agent or other pharmaceutical compounds because they providea more stable environment. Salts dissolved in buffered solutions (whichalso can provide pH control or maintenance) are utilized as diluents,including, but not limited to a phosphate buffered saline solution. Inother embodiments, the gel formulation is isotonic with the endolymph orthe perilymph: depending on the portion of the cochlea that thefree-radical modulating agent formulation is targeted. Isotonicformulations are provided by the addition of a tonicity agent. Suitabletonicity agents include, but are not limited to any pharmaceuticallyacceptable sugar, salt or any combinations or mixtures thereof, such as,but not limited to dextrose and sodium chloride. In further embodiments,the tonicity agents are present in an amount from about 100 mOsm/kg toabout 500 mOsm/kg. In some embodiments, the tonicity agent is present inan amount from about 200 mOsm/kg to about 400 mOsm/kg, from about 280mOsm/kg to about 320 mOsm/kg. The amount of tonicity agents will dependon the target structure of the pharmaceutical formulation, as describedherein.

Useful tonicity compositions also include one or more salts in an amountrequired to bring osmolality of the composition into an acceptable rangefor the perilymph or the endolymph. Such salts include those havingsodium, potassium or ammonium cations and chloride, citrate, ascorbate,borate, phosphate, bicarbonate, sulfate, thiosulfate or bisulfiteanions; suitable salts include sodium chloride, potassium chloride,sodium thiosulfate, sodium bisulfite and ammonium sulfate.

In some embodiments, the auris-acceptable gel formulations disclosedherein alternatively or additionally contains preservatives to preventmicrobial growth. Suitable auris-acceptable preservatives for use in theenhanced viscosity formulations described herein include, but are notlimited to benzoic acid, boric acid, p-hydroxybenzoates, alcohols,quarternary compounds, stabilized chlorine dioxide, mercurials, such asmerfen and thiomersal, mixtures of the foregoing and the like.

In a further embodiment, the preservative is, by way of example only, afree-radical modulating agent, within the auris-acceptable formulationspresented herein. In one embodiment, the formulation includes apreservative such as by way of example only, methyl paraben, sodiumbisulfite, sodium thiosulfate, ascorbate, chorobutanol, thimerosal,parabens, benzyl alcohol, phenylethanol and others. In anotherembodiment, the methyl paraben is at a concentration of about 0.05% toabout 1.0%, about 0.1% to about 0.2%. In a further embodiment, the gelis prepared by mixing water, methylparaben, hydroxyethylcellulose andsodium citrate. In a further embodiment, the gel is prepared by mixingwater, methylparaben, hydroxyethylcellulose and sodium acetate. In afurther embodiment, the mixture is sterilized by autoclaving at 120° C.for about 20 minutes, and tested for pH, methylparaben concentration andviscosity before mixing with the appropriate amount of the free-radicalmodulating agent disclosed herein.

Suitable auris-acceptable water soluble preservatives which are employedin the drug delivery vehicle include sodium bisulfite, sodiumthiosulfate, ascorbate, chorobutanol, thimerosal, parabens, benzylalcohol, Butylated hydroxytoluene (BHT), phenylethanol and others. Theseagents are present, generally, in amounts of about 0.001% to about 5% byweight or, in the amount of about 0.01 to about 2% by weight. In someembodiments, auris-compatible formulations described herein are free ofpreservatives.

Round Window Membrane Penetration Enhancers

In another embodiment, the formulation further comprises one or moreround window membrane penetration enhancers. Penetration across theround window membrane is enhanced by the presence of round windowmembrane penetration enhancers. Round window membrane penetrationenhancers are chemical entities that facilitate transport ofcoadministered substances across the round window membrane. Round windowmembrane penetration enhancers are grouped according to chemicalstructure. Surfactants, both ionic and non-ionic, such as sodium laurylsulfate, sodium laurate, polyoxyethylene-20-cetyl ether, laureth-9,sodium dodecylsulfate, dioctyl sodium sulfosuccinate,polyoxyethylene-9-lauryl ether (PLE), Tween® 80,nonylphenoxypolyethylene (NP-POE), polysorbates and the like, functionas round window membrane penetration enhancers. Bile salts (such assodium glycocholate, sodium deoxycholate, sodium taurocholate, sodiumtaurodihydrofusidate, sodium glycodihydrofusidate and the like), fattyacids and derivatives (such as oleic acid, caprylic acid, mono- anddi-glycerides, lauric acids, acylcholines, caprylic acids,acylcarnitines, sodium caprates and the like), chelating agents (such asEDTA, citric acid, salicylates and the like), sulfoxides (such asdimethyl sulfoxide (DMSO), decylmethyl sulfoxide and the like), andalcohols (such as ethanol, isopropanol, glycerol, propanediol and thelike) also function as round window membrane penetration enhancers.

In some embodiments, the auris acceptable penetration enhancer is asurfactant comprising an alkyl-glycoside wherein the alkyl glycoside istetradecyl-β-D-maltoside. In some embodiments, the auris acceptablepenetration enhancer is a surfactant comprising an alkyl-glycosidewherein the alkyl glycoside is dodecyl-maltoside. In certain instances,the penetration enhancing agent is a hyaluronidase. In certaininstances, a hyaluronidase is a human or bovine hyaluronidase. In someinstances, a hyaluronidase is a human hyaluronidase (e.g., hyaluronidasefound in human sperm, PH20 (Halozyme), Hyelenex® (Baxter International,Inc.)). In some instances, a hyaluronidase is a bovine hyaluronidase(e.g., bovine testicular hyaluronidase, Amphadase® (AmphastarPharmaceuticals), Hydase® (PrimaPharm, Inc). In some instances, ahyluronidase is an ovine hyaluronidase, Vitrase® (ISTA Pharmaceuticals).In certain instances, a hyaluronidase described herein is a recombinanthyaluronidase. In some instances, a hyaluronidase described herein is ahumanized recombinant hyaluronidase. In some instances, a hyaluronidasedescribed herein is a pegylated hyaluronidase (e.g., PEGPH20(Halozyme)). In addition, the peptide-like penetration enhancersdescribed in U.S. Pat. Nos. 7,151,191, 6,221,367 and 5,714,167, hereinincorporated by references for such disclosure, are contemplated as anadditional embodiment. These penetration enhancers are amino-acid andpeptide derivatives and enable drug absorption by passive transcellulardiffusion without affecting the integrity of membranes or intercellulartight junctions.

Round Window Membrane Permeable Liposomes

Liposomes or lipid particles may also be employed to encapsulate thefree-radical modulating agent formulations or compositions.Phospholipids that are gently dispersed in an aqueous medium formmultilayer vesicles with areas of entrapped aqueous media separating thelipid layers. Sonication, or turbulent agitation, of these multilayerveiscles results in the formation of single layer vesicles, commonlyreferred to as liposomes, with sizes of about 10-1000 nm. Theseliposomes have many advantages as free-radical modulating agents orother pharmaceutical agent carriers. They are biologically inert,biodegradable, non-toxic and non-antigenic. Liposomes are formed invarious sizes and with varying compositions and surface properties.Additionally, they are able to entrap a wide variety of agents andrelease the agent at the site of liposome collapse.

Suitable phospholipids for use in auris-acceptable liposomes here are,for example, phosphatidyl cholines, ethanolamines and serines,sphingomyelins, cardiolipins, plasmalogens, phosphatidic acids andcerebrosides, in particular those which are soluble together with thefree-radical modulating agents herein in non-toxic, pharmaceuticallyacceptable organic solvents. Preferred phospholipids are, for example,phosphatidyl choline, phosphatidyl ethanolmine, phosphatidyl serine,phosphatidyl inositol, lysophosphatidyl choline, phosphatidyl glyceroland the like, and mixtures thereof especially lecithin, e.g. soyalecithin. The amount of phospholipid used in the present formulationrange from about 10 to about 30%, preferably from about 15 to about 25%and in particular is about 20%.

Lipophilic additives may be employed advantageously to modifyselectively the characteristics of the liposomes. Examples of suchadditives include by way of example only, stearylamine, phosphatidicacid, tocopherol, cholesterol, cholesterol hemisuccinate and lanolinextracts. The amount of lipophilic additive used range from 0.5 to 8%,preferably from 1.5 to 4% and in particular is about 2%. Generally, theratio of the amount of lipophilic additive to the amount of phospholipidranges from about 1:8 to about 1:12 and in particular is about 1:10.Said phospholipid, lipophilic additive and the free-radical modulatingagent and other pharmaceutical compounds are employed in conjunctionwith a non-toxic, pharmaceutically acceptable organic solvent systemwhich dissolve said ingredients. Said solvent system not only mustdissolve the free-radical modulating agent completely, but it also hasto allow the formulation of stable single bilayered liposomes. Thesolvent system comprises dimethylisosorbide and tetraglycol (glycofurol,tetrahydrofurfuryl alcohol polyethylene glycol ether) in an amount ofabout 8 to about 30%. In said solvent system, the ratio of the amount ofdimethylisosorbide to the amount of tetraglycol range from about 2:1 toabout 1:3, in particular from about 1:1 to about 1:2.5 and preferably isabout 1:2. The amount of tetraglycol in the final composition thus varyfrom 5 to 20%, in particular from 5 to 15% and preferably isapproximately 10%. The amount of dimethylisosorbide in the finalcomposition thus range from 3 to 10%, in particular from 3 to 7% andpreferably is approximately 5%.

The term “organic component” as used hereinafter refers to mixturescomprising said phospholipid, lipophilic additives and organic solvents.The free-radical modulating agent may be dissolved in the organiccomponent, or other means to maintain full activity of the agent. Theamount of free-radical modulating agent in the final formulation mayrange from 0.1 to 5.0%. In addition, other ingredients such asanti-oxidants may be added to the organic component. Examples includetocopherol, butylated hydroxyanisole, butylated hydroxytoluene, ascorbylpalmitate, ascorbyl oleate and the like.

Liposomal formulations are alternatively prepared, for free-radicalmodulating agents or other pharmaceutical agents that are moderatelyheat-resistant, by (a) heating the phospholipid and the organic solventsystem to about 60-80° C. in a vessel, dissolving the active ingredient,then adding any additional formulating agents, and stirring the mixtureuntil complete dissolution is obtained; (b) heating the aqueous solutionto 90-95° C. in a second vessel and dissolving the preservativestherein, allowing the mixture to cool and then adding the remainder ofthe auxiliary formulating agents and the remainder of the water, andstirring the mixture until complete dissolution is obtained; thuspreparing the aqueous component; (c) transferring the organic phasedirectly into the aqueous component, while homogenizing the combinationwith a high performance mixing apparatus, for example, a high-shearmixer; and (d) adding a viscosity enhancing agent to the resultingmixture while further homogenizing. The aqueous component is optionallyplaced in a suitable vessel which is equipped with a homogenizer andhomogenization is effected by creating turbulence during the injectionof the organic component. Any mixing means or homogenizer which exertshigh shear forces on the mixture may be employed. Generally, a mixercapable of speeds from about 1,500 to 20,000 rpm, in particular fromabout 3,000 to about 6,000 rpm may be employed. Suitable viscosityenhancing agents for use in process step (d) are for example, xanthangum, hydroxypropyl cellulose, hydroxypropyl methylcellulose or mixturesthereof. The amount of viscosity enhancing agent depends on the natureand the concentration of the other ingredients and in general rangesfrom about 0.5 to 2.0%, or approximately 1.5%. In order to preventdegradation of the materials used during the preparation of theliposomal formulation, it is advantageous to purge all solutions with aninert gas such as nitrogen or argon, and to conduct all steps under aninert atmosphere. Liposomes prepared by the above described methodusually contain most of the active ingredient bound in the lipid bilayerand separation of the liposomes from unencapsulated material is notrequired.

In other embodiments, the auris-acceptable formulations, including gelformulations and viscosity-enhanced formulations, further includeexcipients, other medicinal or pharmaceutical agents, carriers,adjuvants, such as preserving, stabilizing, wetting or emulsifyingagents, solution promoters, salts, solubilizers, an antifoaming agent,an antioxidant, a dispersing agent, a wetting agent, a surfactant, andcombinations thereof.

Suitable carriers for use in an auris-acceptable formulation describedherein include, but are not limited to, any pharmaceutically acceptablesolvent compatible with the targeted auris structure's physiologicalenvironment. In other embodiments, the base is a combination of apharmaceutically acceptable surfactant and solvent.

In some embodiments, other excipients include, sodium stearyl fumarate,diethanolamine cetyl sulfate, isostearate, polyethoxylated castor oil,nonoxyl 10, octoxynol 9, sodium lauryl sulfate, sorbitan esters(sorbitan monolaurate, sorbitan monooleate, sorbitan monopalmitate,sorbitan monostearate, sorbitan sesquioleate, sorbitan trioleate,sorbitan tristearate, sorbitan laurate, sorbitan oleate, sorbitanpalmitate, sorbitan stearate, sorbitan dioleate, sorbitansesqui-isostearate, sorbitan sesquistearate, sorbitan tri-isostearate),lecithin pharmaceutical acceptable salts thereof and combinations ormixtures thereof.

In other embodiments, the carrier is a polysorbate. Polysorbates arenonionic surfactants of sorbitan esters. Polysorbates useful in thepresent disclosure include, but are not limited to polysorbate 20,polysorbate 40, polysorbate 60, polysorbate 80 (Tween 80) and anycombinations or mixtures thereof. In further embodiments, polysorbate 80is utilized as the pharmaceutically acceptable carrier.

In one embodiment, water-soluble glycerin-based auris-acceptableenhanced viscosity formulations utilized in the preparation ofpharmaceutical delivery vehicles comprise at least one free-radicalmodulating agent containing at least about 0.1% of the water-solubleglycerin compound or more. In some embodiments, the percentage offree-radical modulating agent is varied between about 1% and about 95%,between about 5% and about 80%, between about 10% and about 60% or moreof the weight or volume of the total pharmaceutical formulation. In someembodiments, the amount of the compound(s) in each therapeuticallyuseful free-radical modulating agent formulation is prepared in such away that a suitable dosage will be obtained in any given unit dose ofthe compound. Factors such as solubility, bioavailability, biologicalhalf-life, route of administration, product shelf life, as well as otherpharmacological considerations are contemplated herein.

If desired, the auris-acceptable pharmaceutical gels also containco-solvents, preservatives, cosolvents, ionic strength and osmolalityadjustors and other excipients in addition to buffering agents. Suitableauris-acceptable water soluble buffering agents are alkali or alkalineearth metal carbonates, phosphates, bicarbonates, citrates, borates,acetates, succinates and the like, such as sodium phosphate, citrate,borate, acetate, bicarbonate, carbonate and tromethamine (TRIS). Theseagents are present in amounts sufficient to maintain the pH of thesystem at 7.4±0.2 and preferably, 7.4. As such, the buffering agent isas much as 5% on a weight basis of the total composition.

Cosolvents are used to enhance free-radical modulating agent solubility,however, some free-radical modulating agents or other pharmaceuticalcompounds are insoluble. These are often suspended in the polymervehicle with the aid of suitable suspending or viscosity enhancingagents.

Moreover, some pharmaceutical excipients, diluents or carriers arepotentially ototoxic. For example, benzalkonium chloride, a commonpreservative, is ototoxic and therefore potentially harmful ifintroduced into the vestibular or cochlear structures. In formulating acontrolled release free-radical modulating agent formulation, it isadvised to avoid or combine the appropriate excipients, diluents orcarriers to lessen or eliminate potential ototoxic components from theformulation, or to decrease the amount of such excipients, diluents orcarriers.

The following are examples of therapeutically acceptable oticformulations:

Example Formulation Example Characteristics Chitosan tunable degradationof matrix in vitro glycerophosphate (CGP) tunable TACE inhibitor releasein vitro: e.g., ~50% of drug released after 24 hrs biodegradablecompatible with drug delivery to the inner ear suitable formacromolecules and hydrophobic drugs PEG-PLGA-PEG triblock tunable highstability: e.g., maintains mechanical integrity polymers >1 month invitro tunable fast release of hydrophilic drugs: e.g., ~50% of drugreleased after 24 hrs, and remainder released over ~5 days tunable slowrelease of hydrophobic drugs: e.g., ~80% released after 8 weeksbiodegradable subcutaneous injection of solution: e.g., gel forms withinseconds and is intact after 1 month PEO-PPO-PEO triblock Tunable sol-geltransition temperature: e.g., decreases copolymers (e.g., withincreasing F127 concentration Pluronic or Poloxameres) (e.g., F127)Chitosan CGP formulation tolerates liposomes: e.g., up to 15 uM/mlglycerophosphate with liposomes. drug-loaded liposomes liposomes tunablyreduce drug release time (e.g., up to 2 weeks in vitro). increase inliposome diameter optionally reduces drug release kinetics (e.g.,liposome size between 100 and 300 nm) release parameters are controlledby changing composition of liposomes

The formulations disclosed herein alternatively encompass anotoprotectant agent in addition to the at least one active agent and/orexcipients, including but not limited to such agents as antioxidants,alpha lipoic acid, calcium, fosfomycin or iron chelators, to counteractpotential ototoxic effects that may arise from the use of specifictherapeutic agents or excipients, diluents or carriers.

Modes of Treatment

Dosing Methods and Schedules

Drugs delivered to the inner ear have been administered systemically viaoral, intravenous or intramuscular routes. However, systemicadministration for pathologies local to the inner ear increases thelikelihood of systemic toxicities and adverse side effects and creates anon-productive distribution of drug in which high levels of drug arefound in the serum and correspondingly lower levels are found at theinner ear.

Intratympanic injection of therapeutic agents is the technique ofinjecting a therapeutic agent behind the tympanic membrane into themiddle and/or inner ear. In one embodiment, the formulations describedherein are administered directly onto the round window membrane viatranstympanic injection. In another embodiment, the free-radicalmodulating agent auris-acceptable formulations described herein areadministered onto the round window membrane via a non-transtympanicapproach to the inner ear. In additional embodiments, the formulationdescribed herein is administered onto the round window membrane via asurgical approach to the round window membrane comprising modificationof the crista fenestrae cochleae.

In one embodiment the delivery system is a syringe and needle apparatusthat is capable of piercing the tympanic membrane and directly accessingthe round window membrane or crista fenestrae cochleae of the aurisinterna. In some embodiments, the needle on the syringe is wider than a18 gauge needle. In another embodiment, the needle gauge is from 18gauge to 31 gauge. In a further embodiment, the needle gauge is from 25gauge to 30 gauge. Depending upon the thickness or viscosity of thefree-radical modulating agent compositions or formulations, the gaugelevel of the syringe or hypodermic needle may be varied accordingly. Inanother embodiment, the internal diameter of the needle can be increasedby reducing the wall thickness of the needle (commonly referred as thinwall or extra thin wall needles) to reduce the possibility of needleclogging while maintaining an adequate needle gauge.

In another embodiment, the needle is a hypodermic needle used forinstant delivery of the gel formulation. The hypodermic needle may be asingle use needle or a disposable needle. In some embodiments, a syringemay be used for delivery of the pharmaceutically acceptable gel-basedfree-radical modulating agent-containing compositions as disclosedherein wherein the syringe has a press-fit (Luer) or twist-on(Luer-lock) fitting. In one embodiment, the syringe is a hypodermicsyringe. In another embodiment, the syringe is made of plastic or glass.In yet another embodiment, the hypodermic syringe is a single usesyringe. In a further embodiment, the glass syringe is capable of beingsterilized. In yet a further embodiment, the sterilization occursthrough an autoclave. In another embodiment, the syringe comprises acylindrical syringe body wherein the gel formulation is stored beforeuse. In other embodiments, the syringe comprises a cylindrical syringebody wherein the free-radical modulating agent pharmaceuticallyacceptable gel-based compositions as disclosed herein is stored beforeuse which conveniently allows for mixing with a suitablepharmaceutically acceptable buffer. In other embodiments, the syringemay contain other excipients, stabilizers, suspending agents, diluentsor a combination thereof to stabilize or otherwise stably store thefree-radical modulating agent or other pharmaceutical compoundscontained therein.

In some embodiments, the syringe comprises a cylindrical syringe bodywherein the body is compartmentalized in that each compartment is ableto store at least one component of the auris-acceptable free-radicalmodulating agent gel formulation. In a further embodiment, the syringehaving a compartmentalized body allows for mixing of the componentsprior to injection into the auris media or auris interna. In otherembodiments, the delivery system comprises multiple syringes, eachsyringe of the multiple syringes contains at least one component of thegel formulation such that each component is pre-mixed prior to injectionor is mixed subsequent to injection. In a further embodiment, thesyringes disclosed herein comprise at least one reservoir wherein the atleast one reservoir comprises a free-radical modulating agent, or apharmaceutically acceptable buffer, or a viscosity enhancing agent, suchas a gelling agent or a combination thereof. Commercially availableinjection devices are optionally employed in their simplest form asready-to-use plastic syringes with a syringe barrel, needle assemblywith a needle, plunger with a plunger rod, and holding flange, toperform an intratympanic injection.

In some embodiments, the delivery device is an apparatus designed foradministration of therapeutic agents to the middle and/or inner ear. Byway of example only: GYRUS Medical Gmbh offers micro-otoscopes forvisualization of and drug delivery to the round window niche; Arenberghas described a medical treatment device to deliver fluids to inner earstructures in U.S. Pat. Nos. 5,421,818; 5,474,529; and 5,476,446, eachof which is incorporated by reference herein for such disclosure. U.S.patent application Ser. No. 08/874,208, which is incorporated herein byreference for such disclosure, describes a surgical method forimplanting a fluid transfer conduit to deliver therapeutic agents to theinner ear. U.S. Patent Application Publication 2007/0167918, which isincorporated herein by reference for such disclosure, further describesa combined otic aspirator and medication dispenser for intratympanicfluid sampling and medicament application.

The auris-acceptable compositions or formulations containing thefree-radical modulating agent compound(s) described herein areadministered for prophylactic and/or therapeutic treatments. Intherapeutic applications, the free-radical modulating agent compositionsare administered to a patient already suffering from an autoimmunedisease, condition or disorder, in an amount sufficient to cure or atleast partially arrest the symptoms of the disease, disorder orcondition. Amounts effective for this use will depend on the severityand course of the disease, disorder or condition, previous therapy, thepatient's health status and response to the drugs, and the judgment ofthe treating physician.

Frequency of Administration

In some embodiments, a composition disclosed herein is administered toan individual in need thereof once. In some embodiments, a compositiondisclosed herein is administered to an individual in need thereof morethan once. In some embodiments, a first administration of a compositiondisclosed herein is followed by a second administration of a compositiondisclosed herein. In some embodiments, a first administration of acomposition disclosed herein is followed by a second and thirdadministration of a composition disclosed herein. In some embodiments, afirst administration of a composition disclosed herein is followed by asecond, third, and fourth administration of a composition disclosedherein. In some embodiments, a first administration of a compositiondisclosed herein is followed by a second, third, fourth, and fifthadministration of a composition disclosed herein. In some embodiments, afirst administration of a composition disclosed herein is followed by adrug holiday.

The number of times a composition is administered to an individual inneed thereof depends on the discretion of a medical professional, thedisorder, the severity of the disorder, and the individuals's responseto the formulation. In some embodiments, a composition disclosed hereinis administered once to an individual in need thereof with a mild acutecondition. In some embodiments, a composition disclosed herein isadministered more than once to an individual in need thereof with amoderate or severe acute condition. In the case wherein the patient'scondition does not improve, upon the doctor's discretion theadministration of a free-radical modulating agent may be administeredchronically, that is, for an extended period of time, includingthroughout the duration of the patient's life in order to ameliorate orotherwise control or limit the symptoms of the patient's disease orcondition.

In the case wherein the patient's condition does not improve, upon thedoctor's discretion the administration of the free-radical modulatingagent compounds may be administered chronically, that is, for anextended period of time, including throughout the duration of thepatient's life in order to ameliorate or otherwise control or limit thesymptoms of the patient's disease or condition.

In the case wherein the patient's status does improve, upon the doctor'sdiscretion the administration of the free-radical modulating agentcompounds may be given continuously; alternatively, the dose of drugbeing administered may be temporarily reduced or temporarily suspendedfor a certain length of time (i.e., a “drug holiday”). The length of thedrug holiday varies between 2 days and 1 year, including by way ofexample only, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 10 days,12 days, 15 days, 20 days, 28 days, 35 days, 50 days, 70 days, 100 days,120 days, 150 days, 180 days, 200 days, 250 days, 280 days, 300 days,320 days, 350 days, and 365 days. The dose reduction during a drugholiday may be from 10%-100%, including by way of example only 10%, 15%,20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%,90%, 95%, and 100%.

Once improvement of the patient's otic conditions has occurred, amaintenance free-radical modulating agent dose is administered ifnecessary. Subsequently, the dosage or the frequency of administration,or both, is optionally reduced, as a function of the symptoms, to alevel at which the improved disease, disorder or condition is retained.In certain embodiments, patients require intermittent treatment on along-term basis upon any recurrence of symptoms.

The amount of free-radical modulating agent that will correspond to suchan amount will vary depending upon factors such as the particularcompound, disease condition and its severity, according to theparticular circumstances surrounding the case, including, e.g., thespecific free-radical modulating agent being administered, the route ofadministration, the autoimmune condition being treated, the target areabeing treated, and the subject or host being treated. In general,however, doses employed for adult human treatment will typically be inthe range of 0.02-50 mg per administration, preferably 1-15 mg peradministration. The desired dose is presented in a single dose or asdivided doses administered simultaneously (or over a short period oftime) or at appropriate intervals.

In some embodiments, the initial administration is a particularfree-radical modulating agent and the subsequent administration adifferent formulation or free-radical modulating agent.

Pharmacokinetics of Controlled Release Formulations

In one embodiment, the formulations disclosed herein additionallyprovides an immediate release of a free-radical modulator from thecomposition, or within 1 minute, or within 5 minutes, or within 10minutes, or within 15 minutes, or within 30 minutes, or within 60minutes or within 90 minutes. In other embodiments, a therapeuticallyeffective amount of at least one free-radical modulating agent isreleased from the composition immediately, or within 1 minute, or within5 minutes, or within 10 minutes, or within 15 minutes, or within 30minutes, or within 60 minutes or within 90 minutes. In certainembodiments the composition comprises an auris-pharmaceuticallyacceptable gel formulation providing immediate release of at least onefree-radical modulating agent. Additional embodiments of the formulationmay also include an agent that enhances the viscosity of theformulations included herein.

In other or further embodiments, the formulation provides an extendedrelease formulation of at least one free-radical modulating agent. Incertain embodiments, diffusion of at least one free-radical modulatingagent from the formulation occurs for a time period exceeding 5 minutes,or 15 minutes, or 30 minutes, or 1 hour, or 4 hours, or 6 hours, or 12hours, or 18 hours, or 1 day, or 2 days, or 3 days, or 4 days, or 5days, or 6 days, or 7 days, or 10 days, or 12 days, or 14 days, or 18days, or 21 days, or 25 days, or 30 days, or 45 days, or 2 months or 3months or 4 months or 5 months or 6 months or 9 months or 1 year. Inother embodiments, a therapeutically effective amount of at least onefree-radical modulating agent is released from the formulation for atime period exceeding 5 minutes, or 15 minutes, or 30 minutes, or 1hour, or 4 hours, or 6 hours, or 12 hours, or 18 hours, or 1 day, or 2days, or 3 days, or 4 days, or 5 days, or 6 days, or 7 days, or 10 days,or 12 days, or 14 days, or 18 days, or 21 days, or days, or 30 days, or45 days, or 2 months or 3 months or 4 months or 5 months or 6 months or9 months or 1 year.

In other embodiments, the formulation provides both an immediate releaseand an extended release formulation of a free-radical modulating agent.In yet other embodiments, the formulation contains a 0.25:1 ratio, or a0.5:1 ratio, or a 1:1 ratio, or a 1:2 ratio, or a 1:3, or a 1:4 ratio,or a 1:5 ratio, or a 1:7 ratio, or a 1:10 ratio, or a 1:15 ratio, or a1:20 ratio of immediate release and extended release formulations. In afurther embodiment the formulation provides an immediate release of afirst free-radical modulating agent and an extended release of a secondfree-radical modulating agent or other therapeutic agent. In yet otherembodiments, the formulation provides an immediate release and extendedrelease formulation of at least one free-radical modulating agent, andat least one therapeutic agent. In some embodiments, the formulationprovides a 0.25:1 ratio, or a 0.5:1 ratio, or a 1:1 ratio, or a 1:2ratio, or a 1:3, or a 1:4 ratio, or a 1:5 ratio, or a 1:7 ratio, or a1:10 ratio, or a 1:15 ratio, or a 1:20 ratio of immediate release andextended release formulations of a first free-radical modulating agentand second therapeutic agent, respectively.

In a specific embodiment the formulation provides a therapeuticallyeffective amount of at least one free-radical modulating agent (e.g., amodulator of at least one sirtuin) at the site of disease withessentially no systemic exposure. In an additional embodiment theformulation provides a therapeutically effective amount of at least onefree-radical modulating agent at the site of disease with essentially nodetectable systemic exposure. In other embodiments, the formulationprovides a therapeutically effective amount of at least one free-radicalmodulating agent at the site of disease with little or no detectablesystemic exposure.

The combination of immediate release, delayed release and/or extendedrelease free-radical modulating agent compositions or formulations maybe combined with other pharmaceutical agents, as well as the excipients,diluents, stabilizers, tonicity agents and other components disclosedherein. As such, depending upon the free-radical modulating agent used,the thickness or viscosity desired, or the mode of delivery chosen,alternative aspects of the embodiments disclosed herein are combinedwith the immediate release, delayed release and/or extended releaseembodiments accordingly.

In certain embodiments, the pharmacokinetics of the free-radicalmodulating agent formulations described herein are determined byinjecting the formulation on or near the round window membrane of a testanimal (including by way of example, a guinea pig or a chinchilla). At adetermined period of time (e.g., 6 hours, 12 hours, 1 day, 2 days, 3days, 4 days, 5 days, 6 days, and 7 days for testing thepharmacokinetics of a formulation over a 1 week period), the test animalis euthanized and a 5 mL sample of the perilymph fluid is tested. Theinner ear removed and tested for the presence of the free-radicalmodulating agent. As needed, the level of free-radical modulating agentis measured in other organs. In addition, the systemic level of thefree-radical modulating agent is measured by withdrawing a blood samplefrom the test animal. In order to determine whether the formulationimpedes hearing, the hearing of the test animal is optionally tested.

Alternatively, an inner ear is provided (as removed from a test animal)and the migration of the free-radical modulating agent is measured. Asyet another alternative, an in vitro model of a round window membrane isprovided and the migration of the free-radical modulating agent ismeasured.

Kits/Articles of Manufacture

The disclosure also provides kits for preventing, treating orameliorating the symptoms of a disease or disorder in a mammal. Suchkits generally will comprise one or more of the free-radical modulatingagent controlled-release compositions or devices disclosed herein, andinstructions for using the kit. The disclosure also contemplates the useof one or more of the free-radical modulating agent controlled-releasecompositions, in the manufacture of medicaments for treating, abating,reducing, or ameliorating the symptoms of a disease, dysfunction, ordisorder in a mammal, such as a human that has, is suspected of having,or at risk for developing an inner ear disorder.

In some embodiments, kits include a carrier, package, or container thatis compartmentalized to receive one or more containers such as vials,tubes, and the like, each of the container(s) including one of theseparate elements to be used in a method described herein. Suitablecontainers include, for example, bottles, vials, syringes, and testtubes. In other embodiments, the containers are formed from a variety ofmaterials such as glass or plastic.

The articles of manufacture provided herein contain packaging materials.Packaging materials for use in packaging pharmaceutical products arealso presented herein. See, e.g., U.S. Pat. Nos. 5,323,907, 5,052,558and 5,033,252. Examples of pharmaceutical packaging materials include,but are not limited to, blister packs, bottles, tubes, inhalers, pumps,bags, vials, containers, syringes, bottles, and any packaging materialsuitable for a selected formulation and intended mode of administrationand treatment. A wide array of free-radical modulating agentformulations compositions provided herein are contemplated as are avariety of treatments for any disease, disorder, or condition that wouldbenefit by controlled release administration of a free-radical modulatorto the inner ear.

In some embodiments, a kit includes one or more additional containers,each with one or more of various materials (such as reagents, optionallyin concentrated form, and/or devices) desirable from a commercial anduser standpoint for use of a formulation described herein. Non-limitingexamples of such materials include, but not limited to, buffers,diluents, filters, needles, syringes; carrier, package, container, vialand/or tube labels listing contents and/or instructions for use andpackage inserts with instructions for use. A set of instructions isoptionally included. In a further embodiment, a label is on orassociated with the container. In yet a further embodiment, a label ison a container when letters, numbers or other characters forming thelabel are attached, molded or etched into the container itself, a labelis associated with a container when it is present within a receptacle orcarrier that also holds the container, e.g., as a package insert. Inother embodiments a label is used to indicate that the contents are tobe used for a specific therapeutic application. In yet anotherembodiment, a label also indicates directions for use of the contents,such as in the methods described herein.

In certain embodiments, the pharmaceutical compositions are presented ina pack or dispenser device which contains one or more unit dosage formscontaining a compound provided herein. In another embodiment, the packfor example contains metal or plastic foil, such as a blister pack. In afurther embodiment, the pack or dispenser device is accompanied byinstructions for administration. In yet a further embodiment, the packor dispenser is also accompanied with a notice associated with thecontainer in form prescribed by a governmental agency regulating themanufacture, use, or sale of pharmaceuticals, which notice is reflectiveof approval by the agency of the form of the drug for human orveterinary administration. In another embodiment, such notice, forexample, is the labeling approved by the U.S. Food and DrugAdministration for prescription drugs, or the approved product insert.In yet another embodiment, compositions containing a compound providedherein formulated in a compatible pharmaceutical carrier are alsoprepared, placed in an appropriate container, and labeled for treatmentof an indicated condition.

EXAMPLES Example 1 Preparation of a Thermoreversible Gel SRT501Formulation

Quantity (mg/g of Ingredient formulation) SRT501 7.5 methylparaben .75Hypromellose 7.5 Poloxamer 407 135.0 TRIS HCl buffer (0.1 M) 599.25

A 10-g batch of gel formulation containing 1.0% of SRT501 is prepared byfirst suspending Poloxamer 407 (BASF Corp.) in TRIS HCl buffer (0.1 M).The Poloxamer 407 and TRIS are mixed under agitation overnight at 4° C.to ensure complete dissolution of the Poloxamer 407 in the TRIS. Thehypromellose, methylparaben and additional TRIS HCl buffer (0.1 M) isadded. The composition is stirred until dissolution is observed. Asolution of SRT501 is added and the composition is mixed until ahomogenous gel is produced. The mixture is maintained below roomtemperature until use.

Example 2 Preparation of a Mucoadhesive, Thermoreversible Gel SRT501Formulation

Quantity (mg/g of Ingredient formulation) SRT501 7.5 methylparaben .75Hypromellose 7.5 Carbopol 934P 1.5 Poloxamer 407 135 TRIS HCl buffer(0.1 M) 597.75

A 10-g batch of mucoadhesive gel formulation containing 1.0% of SRT501is prepared by first suspending Poloxamer 407 (BASF Corp.) and Carbopol934P in TRIS HCl buffer (0.1 M). The Poloxamer 407, Carbopol 934P andTRIS are mixed under agitation overnight at 4° C. to ensure completedissolution of the Poloxamer 407 and Carbopol 934P in the TRIS. Thehypromellose, methylparaben and additional TRIS HCl buffer (0.1 M) isadded. The composition is stirred until dissolution is observed. TheSRT501 solution is added and the composition is mixed until a homogenousgel is produced. The mixture is maintained below room temperature untiluse.

Example 3 Preparation of a Hydrogel-Based Piceatannol Formulation

Quantity (mg/g of Ingredient formulation) Piceatannol 37.5 paraffin oil750.0 trihydroxystearate 37.5 cetyl dimethicon copolyol 112.5 water qsad 1000 phosphate buffer pH 7.4 qs pH 7.4

The cream-type formulation is first prepared by gently mixingpiceatannol with water until the piceatannol is dissolved. Then, the oilbase is prepared by mixing paraffin oil, trihydroxystearate and cetyldimethicon copolyol at temperatures up to 60° C. The oil base is cooledto room temperature and the piceatannol solution is added. The twophases are mixed until a homogenous, monophasic hydrogel is formed.

Example 4 Preparation of a Gel SRT-2183 Formulation

Quantity (mg/g of Ingredient formulation) SRT-2183 16.0 Chitosan 8.0Glycerophosphate disodium 32.0 water 336.0

A 5 ml solution of acetic acid is titrated to a pH of about 4.0. Thechitosan is added to achieve a pH of about 5.5. The SRT-2183 is thendissolved in the chitosan solution. This solution is sterilized byfiltration. A 5 ml aqueous solution of glycerophosphate disodium is alsoprepared and sterilized. The two solutions are mixed and within 2 h at37° C., the desired gel is formed.

Example 5 Preparation of a Thermoreversible Gel Resveratrol CompositionComprising Micronized Resveratrol Powder

Quantity (mg/g of Ingredient formulation) resveratrol 20.0 BHT 0.002Poloxamer 407 160.0 PBS buffer (0.1 M) 9.0

A 10-g batch of gel formulation containing 2.0% micronized resveratrolis prepared. Micronized resveratrol, 13.8 mg of sodium phosphate dibasicdihydrate USP (Fisher Scientific.)+3.1 mg of sodium phosphate monobasicmonohydrate USP (Fisher Scientific.)+74 mg of sodium chloride USP(Fisher Scientific.) is dissolved with 8.2 g of sterile filtered DIwater and the pH is adjusted to 7.4 with 1 M NaOH. The buffer solutionis chilled down and 1.6 g of poloxamer 407 (BASF Corp., containingapproximately 100 ppm of BHT) is sprinkled into the chilled PBS solutionwhile mixing, solution is mixed until all the poloxamer is dissolved.The poloxamer is sterile filtered using a 33 mm PVDF 0.22 μm sterilesyringe filter (Millipore Corp.) and delivered to 2 mL sterile glassvials (Wheaton) in an aseptic environment, the vials are closed withsterile butyl rubber stoppers (Kimble) and crimped sealed with 13 mm Alseals (Kimble). 20 mg of micronized resveratrol is placed in separateclean depyrogenated vials, the vials are closed with sterile butylrubber stoppers (Kimble) and crimped sealed with 13 mm Al seals(Kimble), vials are dry heat sterilized (Fisher Scientific Isotemp oven)for 7 hours at 140° C. Before administration for the experimentsdescribed herein, 1 mL of the cold poloxamer solution is delivered to avial containing 20 mg of sterile micronized resveratrol using a 21 Gneedle (Becton Dickinson) attached to a 1 mL sterile syringe (BectonDickinson), suspension mixed well by shaking to ensure homogeneity ofthe suspension. The suspension is then withdrawn with the 21 G syringeand the needle is switched to a 27 G needle for administration.

Formulations comprising deferoxamine, SRT-501 and micronized idebenoneare prepared using the above procedure.

Example 6 Preparation of a Thermoreversible Gel Composition ComprisingMicronized Resveratrol Powder and Micronized Idebenone Powder

Quantity (mg/g of Ingredient formulation) resveratrol 15.0 idebenone15.0 BHT 0.002 Poloxamer 407 160.0 PBS buffer (0.1 M) 9.0

A 10-g batch of gel formulation containing 2.0% (micronized resveratroland micronized idebenone) is prepared. Micronized resveratrol,micronized idebenone, 13.8 mg of sodium phosphate dibasic dihydrate USP(Fisher Scientific.)+3.1 mg of sodium phosphate monobasic monohydrateUSP (Fisher Scientific.)+74 mg of sodium chloride USP (FisherScientific.) is dissolved with 8.2 g of sterile filtered DI water andthe pH is adjusted to 7.4 with 1 M NaOH. The buffer solution is chilleddown and 1.6 g of poloxamer 407 (BASF Corp., containing approximately100 ppm of BHT) is sprinkled into the chilled PBS solution while mixing,solution is mixed until all the poloxamer is dissolved. The poloxamer issterile filtered using a 33 mm PVDF 0.22 μm sterile syringe filter(Millipore Corp.) and delivered to 2 mL sterile glass vials (Wheaton) inan aseptic environment, the vials are closed with sterile butyl rubberstoppers (Kimble) and crimped sealed with 13 mm Al seals (Kimble). 20 mgof micronized resveratrol and idebenone is placed in separate cleandepyrogenated vials, the vials are closed with sterile butyl rubberstoppers (Kimble) and crimped sealed with 13 mm Al seals (Kimble), vialsare dry heat sterilized (Fisher Scientific Isotemp oven) for 7 hours at140° C. Before administration for the experiments described herein, 1 mLof the cold poloxamer solution is delivered to a vial containing 20 mgof sterile micronized resveratrol and idebenone using a 21 G needle(Becton Dickinson) attached to a 1 mL sterile syringe (BectonDickinson), suspension mixed well by shaking to ensure homogeneity ofthe suspension. The suspension is then withdrawn with the 21 G syringeand the needle is switched to a 27 G needle for administration.

Example 7 Effect of pH on Degradation Products for Autoclaved 17%Poloxamer 407NF/2% Otic Agent in PBS Buffer

A stock solution of a 17% poloxamer 407/2% otic agent is prepared bydissolving 351.4 mg of sodium chloride (Fisher Scientific), 302.1 mg ofsodium phosphate dibasic anhydrous (Fisher Scientific), 122.1 mg ofsodium phosphate monobasic anhydrous (Fisher Scientific) and anappropriate amount of an otic agent with 79.3 g of sterile filtered DIwater. The solution is cooled down in a ice chilled water bath and then17.05 g of poloxamer 407NF (SPECTRUM CHEMICALS) is sprinkled into thecold solution while mixing. The mixture is further mixed until thepoloxamer is completely dissolved. The pH for this solution is measured.

17% poloxamer 407/2% otic agent in PBS pH of 5.3. Take an aliquot(approximately 30 mL) of the above solution and adjust the pH to 5.3 bythe addition of 1 M HCl.

17% poloxamer 407/2% otic agent in PBS pH of 8.0. Take an aliquot(approximately 30 mL) of the above stock solution and adjust the pH to8.0 by the addition of 1 M NaOH.

A PBS buffer (pH 7.3) is prepared by dissolving 805.5 mg of sodiumchloride (Fisher Scientific), 606 mg of sodium phosphate dibasicanhydrous (Fisher Scientific), 247 mg of sodium phosphate monobasicanhydrous (Fisher Scientific), then QS to 200 g with sterile filtered DIwater.

A 2% solution of an otic agent in PBS pH 7.3 is prepared by dissolvingan appropriate amount of the otic agent in the PBS buffer and QS to 10 gwith PBS buffer.

One mL samples are individually placed in 3 mL screw cap glass vials(with rubber lining) and closed tightly. The vials are placed in aMarket Forge-sterilmatic autoclave (settings, slow liquids) andsterilized at 250° F. for 15 minutes. After the autoclave the samplesare left to cool down to room temperature and then placed inrefrigerator. The samples are homogenized by mixing the vials whilecold.

Appearance (e.g., discoloration and/or precipitation) is observed andrecorded. HPLC analysis is performed using an Agilent 1200 equipped witha Luna C18(2) 3 μm, 100 Å, 250×4.6 mm column) using a 30-80 acetonitrilegradient (1-10 min) of (water-acetonitrile mixture containing 0.05%TFA), for a total run of 15 minutes. Samples are diluted by taking 30 μLof sample and dissolved with 1.5 mL of a 1:1 acetonitrile water mixture.Purity of the otic agent in the autoclaved samples is recorded.

Formulations comprising deferoxamine, resveratrol and micronizedidebenone, prepared according to the procedure above, are tested usingthe above procedure to determine the effect of pH on degradation duringthe autoclaving step.

Example 8 Effect of Autoclaving on the Release Profile and Viscosity ofa 17% Poloxamer 407NF/2% Otic Agent in PBS

An aliquot of a sample (autoclaved and not autoclaved) is evaluated forrelease profile and viscosity measurement to evaluate the impact of heatsterilization on the properties of the gel.

Dissolution is performed at 37° C. in snapwells (6.5 mm diameterpolycarbonate membrane with a pore size of 0.4 μm). 0.2 mL of gel isplaced into snapwell and left to harden, then 0.5 mL is placed intoreservoir and shaken using a Labline orbit shaker at 70 rpm. Samples aretaken every hour (0.1 mL withdrawn and replace with warm buffer).Samples are analyzed for poloxamer concentration by UV at 624 nm usingthe cobalt thiocyanate method, against an external calibration standardcurve. In brief, 20 μL of the sample is mixed with 1980 μL of a 15 mMcobalt thiocyanate solution and absorbance measured at 625 nm, using aEvolution 160 UV/Vis spectrophotometer (Thermo Scientific).

The released otic agent is fitted to the Korsmeyer-Peppas equation

$\frac{Q}{Q_{\alpha}} = {{kt}^{n} + b}$

where Q is the amount of otic agent released at time t, Q, is theoverall released amount of otic agent, k is a release constant of thenth order, n is a dimensionless number related to the dissolutionmechanism and b is the axis intercept, characterizing the initial burstrelease mechanism wherein n=1 characterizes an erosion controlledmechanism. The mean dissolution time (MDT) is the sum of differentperiods of time the drug molecules stay in the matrix before release,divided by the total number of molecules and is calculated by:

${M\; D\; T} = \frac{{nk}^{{- 1}/n}}{n + 1}$

Viscosity measurements are performed using a Brookfield viscometerRVDV-II+P with a CPE-51 spindle rotated at 0.08 rpm (shear rate of 0.31s⁻¹), equipped with a water jacketed temperature control unit(temperature ramped from 15-34° C. at 1.6° C./min). Tgel is defined asthe inflection point of the curve where the increase in viscosity occursdue to the sol-gel transition.

Formulations comprising deferoxamine, resveratrol and micronizedidebenone, prepared according to the procedures described above, aretested using the procedure described above to determine Tgel.

Example 9 Effect of Addition of a Secondary Polymer on the DegradationProducts and Viscosity of a Formulation Containing 2% Otic Agent and 17%Poloxamer 407NF after Heat Sterilization (Autoclaving)

Solution A. A solution of pH 7.0 comprising sodiumcarboxymethylcellulose (CMC) in PBS buffer is prepared by dissolving178.35 mg of sodium chloride (Fisher Scientific), 300.5 mg of sodiumphosphate dibasic anhydrous (Fisher Scientific), 126.6 mg of sodiumphosphate monobasic anhydrous (Fisher Scientific) dissolved with 78.4 ofsterile filtered DI water, then 1 g of Blanose 7M65 CMC (Hercules,viscosity of 5450cP @2%) is sprinkled into the buffer solution andheated to aid dissolution, and the solution is then cooled down.

A solution of pH 7.0 comprising 17% poloxamer 407NF/1% CMC/2% otic agentin PBS buffer is made by cooling down 8.1 g of solution A in a icechilled water bath and then adding an appropriate amount of an oticagent followed by mixing. 1.74 g of poloxamer 407NF (Spectrum Chemicals)is sprinkled into the cold solution while mixing. The mixture is furthermixed until all the poloxamer is completely dissolved.

Two mL of the above sample is placed in a 3 mL screw cap glass vial(with rubber lining) and closed tightly. The vial is placed in a MarketForge-sterilmatic autoclave (settings, slow liquids) and sterilized at250° F. for 25 minutes. After autoclaving the sample is left to cooldown to room temperature and then placed in refrigerator. The sample ishomogenized by mixing while the vials are cold.

Precipitation or discoloration are observed after autoclaving. HPLCanalysis is performed using an Agilent 1200 equipped with a Luna C18(2)3 μm, 100 Å, 250×4.6 mm column) using a 30-80 acetonitrile gradient(1-10 min) of (water-acetonitrile mixture containing 0.05% TFA), for atotal run of 15 minutes. Samples are diluted by taking 30 μL of sampleand dissolving with 1.5 mL of a 1:1 acetonitrile water mixture. Purityof the otic agent in the autoclaved samples is recorded.

Viscosity measurements are performed using a Brookfield viscometerRVDV-II+P with a CPE-51 spindle rotated at 0.08 rpm (shear rate of 0.31s⁻¹), equipped with a water jacketed temperature control unit(temperature ramped from 15-34° C. at 1.6° C./min). Tgel is defined asthe inflection point of the curve where the increase in viscosity occursdue to the sol-gel transition.

Dissolution is performed at 37° C. for the non-autoclaved sample insnapwells (6.5 mm diameter polycarbonate membrane with a pore size of0.4 μm), 0.2 mL of gel is placed into snapwell and left to harden, then0.5 mL is placed into reservoir and shaken using a Labline orbit shakerat 70 rpm. Samples are taken every hour (0.1 mL withdrawn and replacedwith warm buffer). Samples are analyzed for otic agent concentration byUV at 245 nm, against an external calibration standard curve.

Formulations comprising deferoxamine, resveratrol and micronizedidebenone, are tested using the above procedure to determine the effectaddition of a secondary polymer on the degradation products andviscosity of a formulation containing 2% otic agent and 17% poloxamer407NF after heat sterilization (autoclaving).

Example 10 Effect of Buffer Type on the Degradation Products forFormulations Containing Poloxamer 407NF after Heat Sterilization(Autoclaving)

A TRIS buffer is made by dissolving 377.8 mg of sodium chloride (FisherScientific), and 602.9 mg of Tromethamine (Sigma Chemical Co.) then QSto 100 g with sterile filtered DI water, pH is adjusted to 7.4 with 1MHCl.

Stock Solution Containing 25% Poloxamer 407 Solution in TRIS Buffer:

Weigh 45 g of TRIS buffer, chill in an ice chilled bath then sprinkleinto the buffer, while mixing, 15 g of poloxamer 407 NF (SpectrumChemicals). The mixture is further mixed until all the poloxamer iscompletely dissolved.

A series of formulations is prepared with the above stock solution. Anappropriate amount of otic agent (or salt or prodrug thereof) and/orotic agent as micronized/coated/liposomal particles (or salt or prodrugthereof) is used for all experiments.

Stock Solution (pH 7.3) Containing 25% Poloxamer 407 Solution in PBSBuffer:

PBS buffer described above is used. Dissolve 704 mg of sodium chloride(Fisher Scientific), 601.2 mg of sodium phosphate dibasic anhydrous(Fisher Scientific), 242.7 mg of sodium phosphate monobasic anhydrous(Fisher Scientific) with 140.4 g of sterile filtered DI water. Thesolution is cooled down in an ice chilled water bath and then 50 g ofpoloxamer 407NF (SPECTRUM CHEMICALS) is sprinkled into the cold solutionwhile mixing. The mixture is further mixed until the poloxamer iscompletely dissolved.

A series of formulations is prepared with the above stock solution. Anappropriate amount of otic agent (or salt or prodrug thereof) and/orotic agent as micronized/coated/liposomal particles (or salt or prodrugthereof) is used for all experiments.

Tables 2 and 3 list samples prepared using the procedures describedabove. An appropriate amount of otic agent is added to each sample toprovide a final concentration of 2% otic agent in the sample.

TABLE 2 Preparation of samples containing TRIS buffer 25% Stock SolutionTRIS Buffer Sample pH (g) (g) 20% P407/2% otic agent/TRIS 7.45 8.01 1.8218% P407/2% otic agent/TRIS 7.45 7.22 2.61 16% P407/2% otic agent/TRIS7.45 6.47 3.42 18% P407/2% otic agent/TRIS 7.4 7.18 2.64  4% oticagent/TRIS 7.5 — 9.7  2% otic agent/TRIS 7.43 — 5  1% otic agent/TRIS7.35 — 5  2% otic agent/TRIS 7.4 — 4.9 (suspension)

TABLE 3 Preparation of samples containing PBS buffer (pH of 7.3) 25%Stock Solution Sample in PBS (g) PBS Buffer (g) 20% P407/2% otic agent/8.03 1.82 PBS 18% P407/2% otic agent/ 7.1 2.63 PBS 16% P407/2% oticagent/ 6.45 3.44 PBS 18% P407/2% otic agent/ — 2.63 PBS  2% oticagent/PBS — 4.9

One mL samples are individually placed in 3 mL screw cap glass vials(with rubber lining) and closed tightly. The vials are placed in aMarket Forge-sterilmatic autoclave (setting, slow liquids) andsterilized at 250° F. for 25 minutes. After the autoclaving the samplesare left to cool down to room temperature. The vials are placed in therefrigerator and mixed while cold to homogenize the samples.

HPLC analysis is performed using an Agilent 1200 equipped with a LunaC18(2) 3 μm, 100 Å, 250×4.6 mm column) using a 30-80 acetonitrilegradient (1-10 min) of (water-acetonitrile mixture containing 0.05%TFA), for a total run of 15 minutes. Samples are diluted by taking 30 μLof sample and dissolving with 1.5 mL of a 1:1 acetonitrile watermixture. Purity of the otic agent in the autoclaved samples is recorded.The stability of formulations in TRIS and PBS buffers is compared.

Viscosity measurements are performed using a Brookfield viscometerRVDV-II+P with a CPE-51 spindle rotated at 0.08 rpm (shear rate of 0.31s⁻¹), equipped with a water jacketed temperature control unit(temperature ramped from 15-34° C. at 1.6° C./min). Tgel is defined asthe inflection point of the curve where the increase in viscosity occursdue to the sol-gel transition. Only formulations that show no changeafter autoclaving are analyzed.

Formulations comprising deferoxamine, resveratrol and micronizedidebenone, are tested using the above procedure to determine the effectaddition of a secondary polymer on the degradation products andviscosity of a formulation containing 2% otic agent and 17% poloxamer407NF after heat sterilization (autoclaving). Stability of formulationscontaining micronized otic agent is compared to non-micronized oticagent formulation counterparts.

Example 11 Pulsed Release Otic Formulations

A combination of deferoxamine and deferoxamine hydrochloride (ratio of1:1) is used to prepare a pulsed release otic agent formulation usingthe procedures described herein. 20% of the delivered dose ofresveratrol is solubilized in a 17% poloxamer solution of example 7 withthe aid of beta-cyclodextrins. The remaining 80% of the otic agent isthen added to the mixture and the final formulation is prepared usingany procedure described herein.

Pulsed release formulations comprising resveratrol, SRT-501 andmicronized idebenone, prepared according to the procedures and examplesdescribed herein, are tested using procedures described herein todetermine pulse release profiles.

Example 12 Preparation of a 17% Poloxamer 407/2% Otic Agent/78 ppm EVANSBlue in PBS

A Stock solution of Evans Blue (5.9 mg/mL) in PBS buffer is prepared bydissolving 5.9 mg of Evans Blue (Sigma Chemical Co) with 1 mL of PBSbuffer (from example 7).

A Stock solution containing 25% Poloxamer 407 solution in PBS buffer isused in this study. An appropriate amount of an otic agent is added tothe stock solution to prepare formulations comprising 2% of an oticagent (Table 4).

TABLE 4 Preparation of poloxamer 407 samples containing Evans Blue 25%P407 in Evans Blue Sample ID PBS (g) PBS Buffer (g) Solution (μL) 17%P407/2% otic agent/ 13.6 6 265 EB 20% P407/2% otic agent/ 16.019 3.62265 EB 25% P407/2% otic agent/ 19.63 — 265 EB

Formulations comprising deferoxamine, resveratrol and micronizedidebenone, are prepared according to the procedures described above andare sterile filtered through 0.22 μm PVDF syringe filters (Milliporecorporation), and autoclaved.

The above formulations are dosed to guinea pigs in the middle ear byprocedures described herein and the ability of formulations to gel uponcontact and the location of the gel is identified after dosing and at 24hours after dosing.

Example 13 Terminal Sterilization of Poloxamer 407 Formulations with andwithout a Visualization Dyes

17% poloxamer407/2% otic agent/in phosphate buffer, pH 7.3: Dissolve 709mg of sodium chloride (Fisher Scientific), 742 mg of sodium phosphatedibasic dehydrate USP (Fisher Scientific), 251.1 mg of sodium phosphatemonobasic monohydrate USP (Fisher Scientific) and an appropriate amountof an otic agent with 158.1 g of sterile filtered DI water. The solutionis cooled down in an ice chilled water bath and then 34.13 g ofpoloxamer 407NF (Spectrum chemicals) is sprinkled into the cold solutionwhile mixing. The mixture is further mixed until the poloxamer iscompletely dissolved.

17% poloxamer407/2% otic agent/59 ppm Evans blue in phosphate buffer:Take two mL of the 17% poloxamer407/2% otic agent/in phosphate buffersolution and add 2 mL of a 5.9 mg/mL Evans blue (Sigma-Aldrich chemicalCo) solution in PBS buffer.

25% poloxamer407/2% otic agent/in phosphate buffer: Dissolve 330.5 mg ofsodium chloride (Fisher Scientific), 334.5 mg of sodium phosphatedibasic dehydrate USP (Fisher Scientific), 125.9 mg of sodium phosphatemonobasic monohydrate USP (Fisher Scientific) and an appropriate amountof an otic agent with 70.5 g of sterile filtered DI water.

The solution is cooled down in an ice chilled water bath and then 25.1 gof poloxamer 407NF (Spectrum chemicals) is sprinkled into the coldsolution while mixing. The mixture is further mixed until the poloxameris completely dissolved.

25% poloxamer407/2% otic agent/59 ppm Evans blue in phosphate buffer:Take two mL of the 25% poloxamer407/2% otic agent/in phosphate buffersolution and add 2 mL of a 5.9 mg/mL Evans blue (Sigma-Aldrich chemicalCo) solution in PBS buffer.

Place 2 mL of formulation into a 2 mL glass vial (Wheaton serum glassvial) and seal with 13 mm butyl str (kimble stoppers) and crimp with a13 mm aluminum seal. The vials are placed in a Market Forge-sterilmaticautoclave (settings, slow liquids) and sterilized at 250° F. for 25minutes. After the autoclaving the samples are left to cool down to roomtemperature and then placed in refrigeration. The vials are placed inthe refrigerator and mixed while cold to homogenize the samples. Samplediscoloration or precipitation after autoclaving is recorded.

HPLC analysis is performed using an Agilent 1200 equipped with a LunaC18(2) 3 μm, 100 Å, 250×4.6 mm column) using a 30-95 methanol:acetatebuffer pH 4 gradient (1-6 min), then isocratic for 11 minutes, for atotal run of 22 minutes. Samples are diluted by taking 30 μL of sampleand dissolved with 0.97 mL of water. The main peaks are recorded. Puritybefore autoclaving is greater than 99% using this method.

Viscosity measurements are performed using a Brookfield viscometerRVDV-II+P with a CPE-51 spindle rotated at 0.08 rpm (shear rate of 0.31s⁻¹), equipped with a water jacketed temperature control unit(temperature ramped from 15-34° C. at 1.6° C./min). Tgel is defined asthe inflection point of the curve where the increase in viscosity occursdue to the sol-gel transition.

Formulations comprising deferoxamine, resveratrol and micronizedidebenone, prepared according to the procedures described herein, aretested using the above procedures to determine stability of theformulations.

Example 14 In Vitro Comparison of Relase Profile

Dissolution is performed at 37° C. in snapwells (6.5 mm diameterpolycarbonate membrane with a pore size of 0.4 μm), 0.2 mL of a gelformulation described herein is placed into snapwell and left to harden,then 0.5 mL buffer is placed into reservoir and shaken using a Lablineorbit shaker at 70 rpm. Samples are taken every hour (0.1 mL withdrawnand replace with warm buffer). Samples are analyzed for otic agentconcentration by UV at 245 nm against an external calibration standardcurve. Pluronic concentration is analyzed at 624 nm using the cobaltthiocyanate method. Relative rank-order of mean dissolution time (MDT)as a function of % P407 is determined. A linear relationship between theformulations mean dissolution time (MDT) and the P407 concentrationindicates that the otic agent is released due to the erosion of thepolymer gel (poloxamer) and not via diffusion. A non-linear relationshipindicates release of otic agent via a combination of diffusion and/orpolymer gel degradation.

Alternatively, samples are analyzed using the method described by LiXin-Yu paper [Acta Pharmaceutica Sinica 2008, 43(2):208-203] andRank-order of mean dissolution time (MDT) as a function of % P407 isdetermined.

Formulations comprising deferoxamine, resveratrol and micronizedidebenone, prepared according to the procedures described herein, aretested using the above procedure to determine the release profile of theotic agents.

Example 15 In Vitro Comparison of Gelation Temperature

The effect of Poloxamer 188 and an otic agent on the gelationtemperature and viscosity of Poloxamer 407 formulations is evaluatedwith the purpose of manipulating the gelation temperature.

A 25% Poloxamer 407 stock solution in PBS buffer and the PBS solutiondescribed above are used. Poloxamer 188NF from BASF is used. Anappropriate amount of otic agent is added to the solutions described inTable 5 to provide a 2% formulation of the otic agent.

TABLE 5 Preparation of samples containing poloxamer 407/poloxamer 18825% P407 Stock Poloxamer PBS Buffer Sample Solution (g) 188 (mg) (g) 16%P407/10% P188 3.207 501 1.3036 17% P407/10% P188 3.4089 500 1.1056 18%P407/10% P188 3.6156 502 0.9072 19% P407/10% P188 3.8183 500 0.7050 20%P407/10% P188 4.008 501 0.5032 20% P407/5% P188 4.01 256 0.770

Mean dissolution time, viscosity and gel temperature of the aboveformulations are measured using procedures described herein.

An equation is fitted to the data obtained and can be utilized toestimate the gelation temperature of F127/F68 mixtures (for 17-20% F127and 0-10% F68).

T _(gel)=−1.8(% F127)+1.3(% F68)+53

An equation is fitted to the data obtained and can be utilized toestimate the Mean Dissolution Time (hr) based on the gelationtemperature of F127/F68 mixtures (for 17-25% F127 and 0-10% F68), usingresults obtained in examples above.

MDT=−0.2(T _(gel))+8

Formulations comprising deferoxamine, resveratrol and micronizedidebenone, are prepared by addition of an appropriate amount of oticagents to the solutions described in Table 5. The gel temperature of theformulations is determined using the procedure described above.

Example 16 Determination of Temperature Range for Sterile Filtration

The viscosity at low temperatures is measured to help guide thetemperature range at which the sterile filtration needs to occur toreduce the possibility of clogging.

Viscosity measurements are performed using a Brookfield viscometerRVDV-II+P with a CPE-40 spindle rotated at 1, 5 and 10 rpm (shear rateof 7.5, 37.5 and 75 s⁻¹), equipped with a water jacketed temperaturecontrol unit (temperature ramped from 10-25° C. at 1.6° C./min).

The Tgel of a 17% Pluronic P407 is determined as a function ofincreasing concentration of otic agent. The increase in Tgel for a 17%pluronic formulation is estimated by:

ΔT_(gel)=0.93[% otic agent]

Formulations comprising deferoxamine, resveratrol and micronizedidebenone, prepared according to procedures described herein, are testedusing the above procedure to determine the temperature range for sterilefiltration. The effect of addition of increased amounts of otic agent onthe Tgel, and the apparent viscosity of the formulations is recorded.

Example 17 Determination of Manufacturing Conditions

TABLE 6 Viscosity of potential formulations at manufacturing/filtrationconditions. Apparent Viscosity^(a) (cP) Sample 5° C. below Tgel 20° C.Temperature @ 100 cP Placebo 52 cP @ 17° C. 120 cP   19° C. 17% P407/2%90 cP @ 18° C. 147 cP 18.5° C. otic agent 17% P407/6% 142 cP @ 22° C. 105 cP 19.7° C. otic agent ^(a)Viscosity measured at a shear rate of37.5 s⁻¹

An 8 liter batch of a 17% P407 placebo is manufactured to evaluate themanufacturing/filtration conditions. The placebo is manufactured byplacing 6.4 liters of DI water in a 3 gallon SS pressure vessel, andleft to cool down in the refrigerator overnight. The following morningthe tank is taken out (water temperature 5° C., RT 18° C.) and 48 g ofsodium chloride, 29.6 g of sodium phosphate dibasic dehydrate and 10 gof sodium phosphate monobasic monohydrate is added and dissolved with anoverhead mixer (IKA RW20 @1720 rpm). Half hour later, once the buffer isdissolved (solution temperature 8° C., RT 18° C.), 1.36 kg of poloxamer407 NF (spectrum chemicals) is slowly sprinkled into the buffer solutionin a 15 minute interval (solution temperature 12° C., RT 18° C.), thenspeed is increased to 2430 rpm. After an additional one hour mixing,mixing speed is reduced to 1062 rpm (complete dissolution).

The temperature of the room is maintained below 25° C. to retain thetemperature of the solution at below 19° C. The temperature of thesolution is maintained at below 19° C. up to 3 hours of the initiationof the manufacturing, without the need to chill/cool the container.

Three different Sartoscale (Sartorius Stedim) filters with a surfacearea of 17.3 cm² are evaluated at 20 psi and 14° C. of solution

1) Sartopore 2, 0.2 μm 5445307HS-FF (PES), flow rate of 16 mL/min

2) Sartobran P, 0.2 μm 5235307HS-FF (cellulose ester), flow rate of 12mL/min

3) Sartopore 2 XLI, 0.2 μm 54453071S-FF (PES), flow rate of 15 mL/min

Sartopore 2 filter 5441307H4-SS is used, filtration is carried out atthe solution temperature using a 0.45, 0.2 μm Sartopore 2150 sterilecapsule (Sartorius Stedim) with a surface area of 0.015 m² at a pressureof 16 psi. Flow rate is measured at approximately 100 mL/min at 16 psi,with no change in flow rate while the temperature is maintained in the6.5-14° C. range. Decreasing pressure and increasing temperature of thesolution causes a decrease in flow rate due to an increase in theviscosity of the solution. Discoloration of the solution is monitoredduring the process.

TABLE 7 Predicted filtration time for a 17% poloxamer 407 placebo at asolution temperature range of 6.5-14° C. using Sartopore 2, 0.2 μmfilters at a pressure of 16 psi of pressure. Estimated flow rate Time tofilter 8 L Filter Size (m²) (mL/min) (estimated) Sartopore 2, size 40.015 100 mL/min 80 min Sartopore 2, size 7 0.05 330 mL/min 24 minSartopore 2, size 8 0.1 670 mL/min 12 min

Viscosity, Tgel and UV/Vis absorption is checked before filtrationevaluation. Pluronic UV/Vis spectra are obtained by a Evolution 160UV/Vis (Thermo Scientific). A peak in the range of 250-300 nm isattributed to BHT stabilizer present in the raw material (poloxamer).Table 8 lists physicochemical properties of the above solutions beforeand after filtration.

TABLE 8 Physicochemical properties of 17% poloxamer 407 placebo solutionbefore and after filtration Viscosity^(a) @ 19° C. Absorbance SampleTgel (° C.) (cP) @ 274 nm Before filtration 22 100 0.3181 Afterfiltration 22 100 0.3081 ^(a)Viscosity measured at a shear rate of 37.5s⁻¹

The above process is applicable for manufacture of 17% P407formulations, and includes temperature analysis of the room conditions.Preferably, a maximum temperature of 19° C. reduces cost of cooling thecontainer during manufacturing. In some instances, a jacketed containeris used to further control the temperature of the solution to easemanufacturing concerns.

Example 18 In Vitro Release of Otic Agent from an Autoclaved MicronizedSample

17% poloxamer 407/1.5% otic agent in TRIS buffer: 250.8 mg of sodiumchloride (Fisher Scientific), and 302.4 mg of Tromethamine (SigmaChemical Co.) is dissolved in 39.3 g of sterile filtered DI water, pH isadjusted to 7.4 with 1M HCl. 4.9 g of the above solution is used and anappropriate amount of micronized otic agent is suspended and dispersedwell. 2 mL of the formulation is transferred into a 2 mL glass vial(Wheaton serum glass vial) and sealed with 13 mm butyl styrene (kimblestoppers) and crimped with a 13 mm aluminum seal. The vial is placed ina Market Forge-sterilmatic autoclave (settings, slow liquids) andsterilized at 250° F. for 25 minutes. After the autoclaving the sampleis left to cool down to room temperature. The vial is placed in therefrigerator and mixed while cold to homogenize the sample. Samplediscoloration or precipitation after autoclaving is recorded.

Dissolution is performed at 37° C. in snapwells (6.5 mm diameterpolycarbonate membrane with a pore size of 0.4 μm), 0.2 mL of gel isplaced into snapwell and left to harden, then 0.5 mL PBS buffer isplaced into reservoir and shaken using a Labline orbit shaker at 70 rpm.Samples are taken every hour [0.1 mL withdrawn and replaced with warmPBS buffer containing 2% PEG-40 hydrogenated castor oil (BASF) toenhance otic agent solubility]. Samples are analyzed for otic agentconcentration by UV at 245 nm against an external calibration standardcurve. The release rate is compared to other formulations disclosedherein. MDT time is calculated for each sample.

Solubilization of otic agent in the 17% poloxamer system is evaluated bymeasuring the concentration of the otic agent in the supernatant aftercentrifuging samples at 15,000 rpm for 10 minutes using an eppendorfcentrifuge 5424. Otic agent concentration in the supernatant is measuredby UV at 245 nm against an external calibration standard curve.

Formulations comprising deferoxamine, resveratrol and micronizedidebenone, prepared according to the procedures described herein, aretested using the above procedures to determine release rate of the oticagent from each formulation.

Example 19 Release Rate or MDT and Viscosity of Formulation ContainingSodium Carboxymethyl Cellulose

17% poloxamer 407/2% otic agent/1% CMC (Hercules Blanose 7M): A sodiumcarboxymethylcellulose (CMC) solution (pH 7.0) in PBS buffer is preparedby dissolving 205.6 mg of sodium chloride (Fisher Scientific), 372.1 mgof sodium phosphate dibasic dihydrate (Fisher Scientific), 106.2 mg ofsodium phosphate monobasic monohydrate (Fisher Scientific) in 78.1 g ofsterile filtered DI water. 1 g of Blanose 7M CMC (Hercules, viscosity of533 cP (2%) is sprinkled into the buffer solution and heated to easesolution, solution is then cooled down and 17.08 g poloxamer 407NF(Spectrum Chemicals) is sprinkled into the cold solution while mixing. Aformulation comprising 17% poloxamer 407NF/1% CMC/2% otic agent in PBSbuffer is made adding/dissolving an appropriate amount of otic agent to9.8 g of the above solution, and mixing until all the otic agent iscompletely dissolved.

17% poloxamer 407/2% otic agent/0.5% CMC (Blanose 7M65): A sodiumcarboxymethylcellulose (CMC) solution (pH 7.2) in PBS buffer is preparedby dissolving 257 mg of sodium chloride (Fisher Scientific), 375 mg ofsodium phosphate dibasic dihydrate (Fisher Scientific), 108 mg of sodiumphosphate monobasic monohydrate (Fisher Scientific) in 78.7 g of sterilefiltered DI water. 0.502 g of Blanose 7M65 CMC (Hercules, viscosity of5450 cP @2%) is sprinkled into the buffer solution and heated to easesolution, solution is then cooled down and 17.06 g poloxamer 407NF(Spectrum Chemicals) is sprinkled into the cold solution while mixing. A17% poloxamer 407NF/1% CMC/2% otic agent solution in PBS buffer is madeadding/dissolving an appropriate amount of otic agent to 9.8 g of theabove solution, and mixing until the otic agent is completely dissolved.

17% poloxamer 407/2% otic agent/0.5% CMC (Blanose 7H9): A sodiumcarboxymethylcellulose (CMC) solution (pH 7.3) in PBS buffer is preparedby dissolving 256.5 mg of sodium chloride (Fisher Scientific), 374 mg ofsodium phosphate dibasic dihydrate (Fisher Scientific), 107 mg of sodiumphosphate monobasic monohydrate (Fisher Scientific) in 78.6 g of sterilefiltered DI water, then 0.502 g of Blanose 7H₉CMC (Hercules, viscosityof 5600 cP @1%) is sprinkled to the buffer solution and heated to easesolution, solution is then cooled down and 17.03 g poloxamer 407NF(Spectrum Chemicals) is sprinkled into the cold solution while mixing. A17% poloxamer 407NF/1% CMC/2% otic agent solution in PBS buffer is madeadding/dissolving an appropriate amount of otic agent to 9.8 of theabove solution, and mixing until the otic agent is completely dissolved.

Viscosity measurements are performed using a Brookfield viscometerRVDV-II+P with a CPE-40 spindle rotated at 0.08 rpm (shear rate of 0.6s⁻¹), equipped with a water jacketed temperature control unit(temperature ramped from 10-34° C. at 1.6° C./min). Tgel is defined asthe inflection point of the curve where the increase in viscosity occursdue to the sol-gel transition.

Dissolution is performed at 37° C. in snapwells (6.5 mm diameterpolycarbonate membrane with a pore size of 0.4 μm). 0.2 mL of gel isplaced into snapwell and left to harden, then 0.5 mL PBS buffer isplaced into reservoir and shaken using a Labline orbit shaker at 70 rpm.Samples are taken every hour, 0.1 mL withdrawn and replaced with warmPBS buffer. Samples are analyzed for otic agent concentration by UV at245 nm against an external calibration standard curve. The release rateis compared to the formulations disclosed in above examples, and MDTtime is calculated for each of the above formulations.

Formulations comprising deferoxamine, resveratrol and micronizedidebenone, prepared according to procedures described above, are testedusing the above procedures to determine relationship between releaserate and/or mean dissolution time and viscosity of formulationcontaining sodium carboxymethyl cellulose. Any correlation between themean dissolution time (MDT) and the apparent viscosity (measured at 2°C. below the gelation temperature) is recorded.

Example 20 Effect of Poloxamer Concentration and Otic AgentConcentration on Release Kinetics

A series of compositions comprising varying concentrations of a gellingagent and micronized idebenone is prepared using procedures describedabove. The mean dissolution time (MDT) for each composition in Table 9is determined using procedures described above.

TABLE 9 Preparation of poloxamer/otic agent compositions Sample pH 15.5%P407/1.5% idebenone/PBS 7.4   16% P407/1.5% idebenone/PBS 7.4   17%P407/1.5% idebenone/PBS 7.4 15.5% P407/4.5% idebenone/PBS 7.4   16%P407/4.5% idebenone/PBS 7.4   17% P407/4.5% idebenone/PBS 7.4

The effect of gel strength and otic agent concentration on releasekinetics of an otic agent from the composition or device is determinedby measurement of the MDT for poloxamer, and measurement of MDT for oticagent. The half life of the otic agent and mean residence time of theotic agent is also determined for each formulation by measurement ofconcentration of the otic agent in the perilymph using proceduresdescribed herein.

The apparent viscosity of each composition is measured as describedabove. A thermoreversible polymer gel concentration of about 15.5% in acomposition or device described above provides an apparent viscosity ofabout 270,000 cP. A thermoreversible polymer gel concentration of about16% in a composition or device described above provides an apparentviscosity of about 360,000 cP. A thermoreversible polymer gelconcentration of about 17% in a composition or device described aboveprovides an apparent viscosity of about 480,000 cP.

Compositions comprising deferoxamine, resveratrol and amoxicillin,prepared according to the procedures described above are tested usingthe above procedure to determine release rate of the otic agent fromeach composition.

Example 21 Application of an Enhanced Viscosity Free-Radical ModulatingAgent Formulation onto the Round Window Membrane

A formulation according to Example 7 is prepared and loaded into 5 mlsiliconized glass syringes attached to a 15-gauge luer lock disposableneedle. Lidocaine is topically applied to the tympanic membrane, and asmall incision made to allow visualization into the middle ear cavity.The needle tip is guided into place over the round window membrane, andthe free-radical modulating agent formulation applied directly onto theround-window membrane.

Example 22 In Vivo Testing of Intratympanic Injection of Free-RadicalModulating Agent Formulation in a Guinea Pig

A cohort of 21 guinea pigs (Charles River, females weighing 200-300 g)is intratympanically injected with 50 μL of different P407-otic agentformulations described herein, containing 0 to 50% otic agent. The gelelimination time course for each formulation is determined. A faster gelelimination time course of a formulation indicates lower meandissolution time (MDT). Thus the injection volume and the concentrationof a free-radical modulator in a formulation are tested to determineoptimal parameters for preclinical and clinical studies.

Example 23 In Vivo Extended Release Kinetics

A cohort of 21 guinea pigs (Charles River, females weighing 200-300 g)is intratympanically injected with 50 μL 17% Pluronic F-127 formulationbuffered at 280 mOsm/kg and containing 1.5% to 35% free-radicalmodulating agent by weight of the formulation. Animals are dosed onday 1. The release profile for the formulations is determined based onanalysis of the perilymph.

Example 24 Evaluation of L-(+)-Ergothioneine in a Cisplatin-InducedOtotoxicity Mouse Model

Methods and Materials

Induction of Ototoxicity

Twelve Harlan Sprague-Dawley mice weighing 20 to 24 g are used. Baselineauditory brainstem response (ABR) at 4-20 mHz is measured. The mice aretreated with cisplatin (6 mg/kg of body weight). The cisplatin isdelivered to the aorta by IV infusion.

Treatment

The control group (n=10) are administered saline followingadministration of the cisplatin. The experimental group (n=10) areadministered L-(+)-Ergothioneine (400 mg/kg of body weight) followingadministration of the cisplatin.

Analysis of Results

Electrophysiologic Testing

The hearing threshold for the auditory brainstem response threshold(ABR) to click stimuli for each ear of each animal is initially measuredand 1 week after the experimental procedure. The animals are placed in asingle-walled acoustic booth (Industrial Acoustics Co, Bronx, N.Y., USA)on a heating pad. Subdermal electrodes (Astro-Med, Inc. Grass InstrumentDivision, West Warwick, R.I., USA) were inserted at the vertex (activeelectrode), the mastoid (reference), and the hind leg (ground). Clickstimuli (0.1 millisecond) are computer generated and delivered to aBeyer DT 48, 200 Ohm speaker fitted with an ear speculum for placementin the external auditory meatus. The recorded ABR is amplified anddigitized by a battery-operated preamplifier and input to a Tucker-DavisTechnologies ABR recording system that provides computer control of thestimulus, recording, and averaging functions (Tucker Davis Technology,Gainesville, Fla., USA). Successively decreasing amplitude stimuli arepresented in 5-dB steps to the animal, and the recorded stimulus-lockedactivity is averaged (n=512) and displayed. Threshold is defined as thestimulus level between the record with no visibly detectable responseand a clearly identifiable response.

Example 25 Evaluation of SRT501 on Cisplatin-Induced Ototoxicity

Study Objective

The primary objective of this study will be to assess the safety andefficacy of SRT501 (100 mg) compared with that of placebo in preventingcisplatin-induced ototoxicity.

Methods

Study Design

This will be a phase 3, multicentre, double-blind, randomised,placebo-controlled, parallel group study comparing SRT501 (100 mg) toplacebo in the treatment of Cisplatin-induced ototoxicity. Approximately140 subjects will be enrolled in this study, and randomised (1:1) to 1of 2 treatment groups based on a randomisation sequence prepared bysponsor. Each group will receive either SRT501 (100 mg) or placebo.

Subjects who do not complete the study will not be replaced. Patientswill receive weekly chemotherapy (cisplatin at a dose of 70 mg/m² for 7weeks and daily radiation. Following chemotherapy, patients will receivethe study drug (SRT501 (100 mg) or matching placebo) administered as agel formulation directly onto the subjects' round window membrane for 8weeks.

Each patient will receive a hearing evaluation before each treatmentwith Cisplatin. Two to four weeks after the final dose of Cisplatin,each patient will receive a hearing evaluation. Pre-treatment audiogramwill be compared with the post treatment audiogram to determine thedegree of cisplatin-induced ototoxicity. Patients will thereafterreceive a hearing evaluation at 4-week intervals concomitant with theSRT501 treatment.

Main Criteria for Inclusion

Male or female outpatients aged between 18 and 75 years receivingchemotherapy with Cisplatin. Patients expected to receive a minimum of 3rounds of chemotherapy. If a subject becomes pregnant during the study,she will be immediately withdrawn and no study medication will beadministered.

Exclusion Criteria

Patients who have had middle ear surgery. Patients who have activeexternal or middle ear disease. Patients who have preceding pure toneaverage of >40 dB HL

Example 26 Clinical Trial of Free-Radical Modulating Agent Formulationsin Combination with Surgery

The purpose of this study is to determine if a composition comprising acombination of Resveratrol and Idebenone administered in combinationwith surgery is safe and effective in preventing and/or treating freeradical damage associated with surgery.

Study Type: Interventional

Study Design: This will be a non-inferiority open label study to comparethe current standard of care versus the use of extended releaseintratympanic compositions in combination with surgery. The currentstandard of care requires the use of otic drops for 5-7 dayspost-surgery. The study is designed to test whether administration of asustained release composition at the time of surgery obviates the needfor out-patient treatment. The test hypothesis is that administration ofa single injection of an extended release composition at the time ofsurgery is not inferior to administration of otic drops after surgery.

Inclusion Criteria:

Hearing loss in one or both ears

Patient may not have had otic surgery other than tube placement in thelast year

Patient may not have any disease or condition that would negativelyaffect the conduct of the study

Patient may not require any other systemic free-radical modulating agenttherapy during the study.

Analgesic use (other than acetaminophen) is not allowed

Intact auditory nerve

Exclusion Criteria: Age

Study Protocol: Twenty patients will be divided into two groups. Thefirst group of patients will receive an injection of an extended releasecomposition comprising micronized resveratrol and micronized idebenoneduring the surgical procedure. During the surgical procedure, thesurgeon will clean the ear and while the incision is open, the surgeoninjects a test composition into the middle ear space. The medical deviceis inserted after injection of the extended release composition into themiddle ear space.

The second group of patients will be given ear drops comprisingnon-micronized resveratrol and non-micronized idebenone as immediaterelease components to be administered for 5-7 days after the surgery.

Patients are monitored with weekly follow up visits for one month. Anydifferences in treatment outcomes between the two groups are recorded.

Primary Outcome Measures: Time to cessation of otorrhea as recorded bypatient.

Secondary Outcome Measures: Clinical cure rate; Treatment failures.

The treatment outcome for each group of patients is compared todetermine whether administration of the extended release compositioncomprising resveratrol and idebenone in combination with tympanostomy isno worse than administration of ear drops comprising resveratrol andidebenone after surgery for reduction of otorrhea, and/or damage to otictissues associated with surgery.

While preferred embodiments of the present invention have been shown anddescribed herein, such embodiments are provided by way of example only.Various alternatives to the embodiments described herein are optionallyemployed in practicing the inventions. It is intended that the followingclaims define the scope of the invention and that methods and structureswithin the scope of these claims and their equivalents be coveredthereby.

1. A pharmaceutical composition or device comprising an amount of a free-radical modulator that is therapeutically effective for treating an otic disease or condition associated with free-radical induced damage, the composition or device comprising substantially low degradation products of the free-radical modulating agent, the pharmaceutical composition or device further comprising two or more characteristics selected from: (i) between about 0.1% to about 10% by weight of the free-radical modulating agent, or pharmaceutically acceptable prodrug or salt thereof, (ii) between about 14% to about 21% by weight of a polyoxyethylene-polyoxypropylene triblock copolymer of general formula E106 P70 E106; (iii) sterile water, q.s., buffered to provide a pH between about 5.5 and about 8.0; (iv) multiparticulate free-radical modulating agent; (v) a gelation temperature between about 19° C. to about 42° C.; (vi) less than about 50 colony forming units (cfu) of microbiological agents per gram of formulation; (vii) less than about 5 endotoxin units (EU) per kg of body weight of a subject; (viii) a mean dissolution time of about 30 hours for the free-radical modulating agent; and (ix) an apparent viscosity of about 100,000 cP to about 500,000 cP.
 2. The pharmaceutical composition or device of claim 1, wherein the composition comprises: (i) between about 0.1% to about 10% by weight of the free-radical modulating agent, or pharmaceutically acceptable prodrug or salt thereof, (ii) between about 14% to about 21% by weight of a polyoxyethylene-polyoxypropylene triblock copolymer of general formula E106 P70 E106; (iii) multiparticulate free-radical modulating agent; (iv) a gelation temperature between about 19° C. to about 42° C.; and (v) a mean dissolution time of about 30 hours for the free-radical modulating agent.
 3. The pharmaceutical composition or device of claim 1, wherein the composition or device provides a practical osmolarity between about 200 and 400 mOsm/L.
 4. The pharmaceutical composition or device of claim 1, wherein the composition or device provides a practical osmolarity between about 250 and 320 mOsm/L.
 5. The pharmaceutical composition or device of claim 1, wherein the free-radical modulating agent is released from the composition or device for a period of at least 3 days.
 6. The pharmaceutical composition or device of claim 1, wherein the free-radical modulating agent is released from the composition or device for a period of at least 5 days.
 7. The pharmaceutical composition or device of claim 1, wherein the pharmaceutical composition or device is an auris-acceptable thermoreversible gel.
 8. The pharmaceutical composition or device of claim 1, wherein the polyoxyethylene-polyoxypropylene triblock copolymer is bioeliminated.
 9. The pharmaceutical composition or device of claim 1, further comprising a penetration enhancer.
 10. The pharmaceutical composition or device of claim 1, further comprising a dye.
 11. The pharmaceutical composition or device of claim 1, wherein the free-radical modulating agent is in the form of a neutral molecule, free acid, free base, a salt, a prodrug, or a combination thereof.
 12. The composition or device of claim 1, further comprising the free-radical modulating agent, or pharmaceutically acceptable salt thereof, prodrug or combination thereof as an immediate release agent.
 13. The pharmaceutical composition or device of claim 1, wherein the free-radical modulating agent comprises multiparticulates.
 14. The pharmaceutical composition or device of claim 1, wherein the free-radical modulating agent is essentially in the form of micronized particles.
 15. The pharmaceutical composition or device of claim 1, wherein the free-radical modulating agent is in the form of micronized free-radical modulating agent powder.
 16. The pharmaceutical composition or device of claim 1, wherein the pH of the composition or device is between about 6.0 to about 7.6.
 17. The pharmaceutical composition or device of claim 1, wherein the otic disease or condition is ototoxicity, excitotoxicity, sensorineural hearing loss, or presbycusis.
 18. A method of alleviating free-radical induced damage associated with an otic intervention comprising administering to an individual in need thereof an intratympanic composition or device comprising a therapeutically effective amount of a free-radical modulating agent, the composition or device comprising substantially low degradation products of the free-radical modulating agent, the composition or device further comprising two or more characteristics selected from: (i) between about 0.1% to about 10% by weight of the free-radical modulating agent, or pharmaceutically acceptable prodrug or salt thereof, (ii) between about 14% to about 21% by weight of a polyoxyethylene-polyoxypropylene triblock copolymer of general formula E106 P70 E106; (iii) sterile water, q.s., buffered to provide a pH between about 5.5 and about 8.0; (iv) multiparticulate free-radical modulating agent; (v) a gelation temperature between about 19° C. to about 42° C.; (vi) less than about 50 colony forming units (cfu) of microbiological agents per gram of formulation; (vii) less than about 5 endotoxin units (EU) per kg of body weight of a subject; (viii) a mean dissolution time of about 30 hours; and (ix) an apparent viscosity of about 250,000 cP to about 500,000 cP.
 19. The method of claim 18, wherein the free-radical modulating agent is released from the composition or device for a period of at least 3 days.
 20. The method of claim 18, wherein the free-radical modulating agent is essentially in the form of micronized particles. 